Started by moblet, January 09, 2011, 12:28:56 PM
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Quote from: jamespetts on January 09, 2011, 12:55:57 PMOne other complexity relates to capacity. This is all very well for 'buses, boats and aircraft, but falls apart with trains where there are often separate locomotives and carriages, which can be mixed and matched. One has to look at locomotives as having a haulage capacity (based on the weight of carriages available when they are new, I suppose: carriages get heavier throughout the game); but then carriages themselves need balancing. I wonder how one would incorporate that into a spreadsheet like this? (The same applies for horse-drawn 'buses, of course).
Quote from: Jamesthe revenue per kilometre is fixed, whereas, in Simutrans-Experimental, the revenue per kilometre can vary greatly
Quote from: The HoodI've found in the balancing I've done in Standard the spreadsheet method isn't infallible
Quote from: Jamesall vehicles have a linearly-depreciated age-based resale value
Quote from: Jamescarriages get heavier throughout the game
Quote from: moblet on January 09, 2011, 02:45:06 PMYes, I know enough to know that the revenue side is complicated so I left it for another day. The first question is whether the "lifetime profit factor" is the right measure to use as a benchmark, before getting too carried away. No one's shot that down so far, although sdog is yet to chime in...
QuoteOf course the trains have to be special . What's in my head at the moment is that passenger vs goods as a whole ought to be balanced so that a loco equally suited to either will do equally well hauling either. And we of course have to look at balancing within passenger service and to take into account ancillary carriages, pretty confident we can navigate that, AEO's idea of corralling them into sets might come in handy. Not sure where the comfort model fits into all this yet, I have to get my head around it, and the speedbonus, first. My feeling is that the comfort model won't make too big a mess, it just influences which configuration might be optimal behind a given loco.
QuoteI'm not sure all of the differences in loco capability are going to be very difficult to incorporate, since it sounds like they come down to assumptions of capacity and speed. Yes, locos have differential performance, but we handle that by benchmarking the loco on what it does best, since that's what we expect a skilled player to buy it for. We might do a bit of adjustment in the area of versatility, e.g. if a loco is really only fit for one kind of work there is a higher risk in purchasing it relative to a more versatile unit, so its profit factor should be relatively higher in exchange for that risk. Multiple units won't be hard - we select their optimal configuration, or, if we can't separate them, any one will do.
QuoteThere are so many assumptions underpinning the balancing process that it would be a miracle it we got it right on the first iteration. I think this constitutes a good process for developing the first iteration, and also for converting the feedback from each set into a better subsequent set. We need to have the right levers in the spreadsheet so we can make any kind of adjustment we need to. Just on that point, can Simutrans write a log of journey speeds, loadings, cost, and revenue? Getting actual data out of the sim would help us punch accurate numbers into the balancing process, and to identify where our assumptions were barmy.
QuoteHa! I just asked this question in the other thread. Real-world depreciation is a percentage of remaining value, so the value decreases at a decreasing rate. By scrap value I just mean depreciated value at the end of the nominated life. We don't have to use that terminology in the sim; I wouldn't change it.Something that helps weigh into replacement decisions, but since carriages should outlast locos it may not matter all that much.
QuoteNo one's shot that down so far, although sdog is yet to chime in...
Quote from: jamespetts on January 09, 2011, 03:13:36 PMI suppose that the question is this - in real life, are the lifetime profit factors of all (successful) vehicles of a certain type identical, or at least within a narrow range?
Quote from: JamesIf not, then, given that we're trying to simulate reality, we'll be failing if we adopt this model.
Quote from: JamesMy starting point would be to make the simulation as close to real life as possible in significant respects, then put in numbers as close to real-world numbers as possible and see what happens. Don't we want the outcome to be something that we learn from running the simulation on real data, rather than something that we stipulate from the beginning? Of course, if we then need to adjust the values after testing to make the game playable, that's another matter.
Quote from: JamesFurther complexities are introduced as there are different types of goods traffic: a locomotive good for hauling vast amounts of coal may be less than useful for hauling a fast fish train, and so on.
Quote from: Jamestrain A might be highly profitable on an express, but lose money on a suburban stopping service, whereas train B might be ideally suited to a local stopping service, but be hopeless (and unprofitable) on an express. Running costs, loading times and comfort all have a part to play in this equation (running costs in that local trains will generally have lower revenue but be able to use slower, less powerful and less comfortable vehicles).
Quote from: sdog on January 10, 2011, 07:06:30 AMi'll avoid to look into the spreadsheets now, i have to distract myself a bit less.
Quote from: moblet on January 09, 2011, 12:28:56 PMHere's a simple and merely conceptual first draft.
Quote from: moblet on January 10, 2011, 11:14:38 AMProbably. They must have been profitable, and even if they weren't, from a playability perspective we have to make sure that every vehicle is profitable if operated sensibly, but at the same time that no vehicle wallops all the others of its era in terms of cost performance. Hold that thought. In the real world different owners operated under different local economic and operating conditions so I wouldn't try to simulate actual profitability.
Quote"This model" is not a single set of answers, it is a process for generating consciously constructed, and playable, parameter sets. We will almost certainly fail if we don't have any such process. This is an effort to bring some order and efficiency to what is a very large and intricate task, on a "first crawl, then walk, then run" basis. I don't hear anyone else saying that the ultimate goal is that every number in the sim matches the real world. I believe what people want is a sim that behaves like the real world. Simutrans is a simple model of the real world; to get that model to mimic the real world in the ways we'd like, we have to understand what it does and doesn't capture, what assumptions underpin it, and adapt its inputs accordingly. I believe the goal is to have the sim respond to player decisions in manner similar to how the real world would, and the way to achieve that is not to fixate on real-world numbers, but to identify the real-world dynamics that warrant capture and find the most realistic and efficient way to mimic them. This then drives the data gathering requirements.
QuoteWhat I've already said still applies - we benchmark a loco on the assumption that it will be used for what it does best, e.g. we assume the slow loco hauls something non-perishable, and compare that with the profitability of the faster loco hauling something perishable. If they can't be balanced sensibly then we would have to revisit the goods pricing.
QuoteAgain, I thought we'd already covered this with the idea of benchmarking a vehicle on what it does best. If something isn't technically capable of earning large revenues then it will have to be cheaper to own and run, while if something is capable of earning large revenues it must cost more so it is only worth buying if those revenues will be realised. This benchmarking process can tell us what those cost differences should be, but can only do so after, as a couple of people have observed, the technical performance of the vehicles has been specified. If the cost disparities required to balance the profitabilities of disparate vehicles seem too large, or too small, compared with what they were in reality, or more importantly what makes for good gameplay, then the revenue model(s) can be adjusted to alter the relative profit outcomes in the desired manner.
QuoteEDIT/AFTERTHOUGHT: In accordance with a basic modelling principle of starting off simply and adding complexity, I suggest that we stop confusing ourselves by trying to start with the most complex balancing task, i.e. trains, and focus on mastering the concept and practice of balancing with the simpler modes. Once we have them in our pocket the rail task won't seem so daunting.
Quote from: nerodenI haven't looked at yours, but please look at the spreadsheet I created for this purpose, which is actually in SVN if I remember correctly.
Quote from: nerodenI would like to emphasize again that there is no point in balancing prices until carrying capacity, vehicle weight, power, and tractive effort have been set
Quote from: nerodenIf you're going to work on balancing, I suggest working on infrastructure maintenance costs first. I am really unsure how to balance them properly, but every good way of balancing vehicle prices depends on balancing infrastructure maintenance first.
Quote from: JamesIn many cases the profitabilities would have been comparable; two transport companies in the same country in the same era would all have more or less comparable profit, would they not?
Quote from: Jameslocal 'buses, for example, may never give anything like the return on investment as airliners (even taking into account capital depreciation), but they are necessary in order to get the passengers to and from the airport and enable the aircraft to carry enough passengers in order to be profitable.
Quote from: JamesSome types of transportation might well be orders of magnitude different in profitability to others, but that does not make the less profitable ones not worth pursuing, not least because either they are necessary for linking to the more profitable types to make them work, or because, in a competitive environment, all the opportunities for the more profitable type of transport have been taken away, so the only remaining opportunities are for transportation types with lower profitability.
Quote from: JamesIf we balanced the minibus so that its profitability was, taking into account capital depreciation, identical to that of an airliner, there would be some significant distortion.
Quote from: JamesAvailability of the market is as important a choice for businesses making decisions about where to invest as profit margin, if not more so.
Quote from: JamesSo, indeed, we should balance things that, in the right conditions, no types of vehicles, infrastructure or cargo are, in their own time, impossible to use profitably
Quote from: Jamesbut it would be somewhat arbitrary to equalise the profitability of all types of vehicles,
Quote from: Jamesas they may well not have been equal in reality,
Quote from: JamesIt might be a helpful calibration tool (not least to compare with the profitability of the real thing), and a means to check whether things are indeed profitable within a sensible margin
Quote from: Jamesthe aim of the exercise should be to balance things so that they are as close to reality as possible whilst still being playable
Quote from: JamesA spreadsheet of the sort that you are devising may, therefore, very well be useful, as long as it is designed such as to ensure that all vehicles are somewhere between (and not including) unprofitable and excessively profitable
Quote from: Jamesrather than aiming to equalise the profits entirely.
Quote from: JamesYes, indeed - although I take the view that, when in doubt, one should always err on the side of reality, not least because reality is already balanced for us! If we have a specific reason to fudge the real numbers in a particular way because we know that using the real numbers will result in a particular inaccuracy in gameplay incentives (and, yes, I do agree that the ultimate goal is to make the incentives rather than the numbers themselves realistic), then we can then decide how and how far to depart from reality. So the next issue, then, is this: where are the economic drivers in Simutrans distinctly different from those in reality?
Quote from: JamesAnd, in each such case, is it better fixed by changing the figures or changing the programme itself? I know that we are discussing a number of potential coding changes in the other thread for just this reason.
Quote from: Jamesthings capable of earning greatly higher revenues do, indeed, cost much more than those that aren't.
Quote from: JamesOf course, this isn't always a simple model: a 'bus in a densely populated town might earn vastly more than the very same 'bus in a small village, such that the smaller 'bus built just for small village use will not be less expensive in proportion to its reduced profitability
Quote from: JamesThis could work, although the note of caution that I'd sound in relation to that is that we must know in advance that our model will scale in complexity well: it is possible for any given model to work very well on the simpler tasks, but to fail completely on the more complex ones, so we have to consider the complexities (at least in the abstract) before we finalise the design for our model such as to ensure that it will, indeed, account for those complexities.
Quote from: mobletI haven't reached a conclusion as to whether infrastructure also needs a finite life for balancing to work.
Quote from: JamesI haven't been ignoring this discussion
Quote from: sdog on January 18, 2011, 05:01:38 AMLeasing is not a bad idea, this could also be done purely on the pak-set level making it viable for standard too. Or would it require the monthly cost, instead of 1/km based costs?
Quote from: sdogFor instance in pak128 depreciation slowly drives one bancrupt.
Quote from: sdog on January 18, 2011, 11:27:10 PMat the beginning it's not unusual to build for about 350k of the 400k one has, and buy vehicles for some 5M.
Quote from: AEO on January 19, 2011, 10:30:39 PMWith the current speed bonus and goods settings
Quote from: AEOI also found this page on horse drawn carriage ability, if they are to be used as a base line for calibrating capacity of vehicles.
Quote8.2 - Use recorded car journey time to compare against players' transport's travelling times rather than speed bonus rating for road transport when passengers decide whether to take their car or players' transport.
Quote from: jamespetts on January 24, 2011, 12:48:14 AMFourthly, I am not quite sure what Moblet means by infrastructure having a limited life - can you elaborate, Moblet? Certainly, there are bridges tunnels, cuttings, embankments and stations out there well over a hundred years old in regular and intensive use, not likely to be replaced any time soon.
Quote from: moblet on January 11, 2011, 06:38:55 AMThere are currently no usage-based infrastructure costs, which unbalances early vs mature gameplay (makes it harder to make a profit when you start out), and also doesn't capture the reality that trains wear out rails but boats don't wear out water. If vehicles inflicted wear on their infrastructure that would be simple to include in balancing. One simplistic idea I have is to consider that each mode is, by nature, differentially infrastructure-intensive, and apply an infrastructure capital charge that is the same for each unit of a given mode. So we would benchmark a tram as if its purchase price included a portion of the infrastructure it required. The outcome of this is that the tram would be made cheaper than a bus to buy and own as an individual unit per passenger-km, to compensate for the fact that the player has to pay for more infrastructure to run the tram. The infrastructure loading would be set at a level that assumed a certain level of infrastructure utilisation; the player would not realise the benchmark return on the infrastructure investment if they did not achieve this utilisation (the lower cost of the trams would not offset the infrastructure cost unless a minimum number of trams were bought and used).
Quote from: JamesFifthly, one issue in relation to the use of purchase price to equalise the relative economic performance of vehicles is this: although that model might make sense where the ultimate user of the vehicle has to buy it from a third party manufacturer, in olden times, many vehicles were either built to order or built by the operators themselves (most major railway companies had their own works, for example, although they also subcontracted frequently), and so the purchase cost was not subject to market sensitivity as to its ultimate value. It would seem arbitrary to ignore this significant driver, which might have made a substantial difference to the fortunes of many a transport operator.
Quote from: JamesNot only that, but the cost of vehicles are often set when they are new and before their real success in service has been determined, so even then, the true market value of new vehicles is very unlikely to be reflected in their actual purchase costs.
Quote from: JamesSixthly, there may have been some confusion as to the meaning of comparable profitabilities
Quote from: JamesSeventlhy, on cross-subsidisation, the suggestion was not that certain modes of transport could only be profitable at all when cross-subsidised, but rather the potential for one mode of transport positively to affect the profitability of another must be taken into account in circumstances where the two are likely often to be used in conjunction with each other, or distortions are likely. For example, before the second half of the 20th century, many railway branch lines were, of themselves, barely profitable or even unprofitable, but railways kept them going because they fed the far more profitable main lines. These economics of interconnexion are, to use Moblet's phrase, "primary drivers" in the economics of transport and must be simulated in order for the player's incentives in the game adequately to match real-world economic incentives, and for the transport networks produced by a competent player to be sufficiently similar to those produced by competent managers of transport companies in reality.
Quote from: MobletSince the relative infrastructure costs are significant in this equation, one has to pin down what the infrastructure costs actually are. This is not possible if infrastructure never ages, since, say, the cost per passenger, or cost per tram km, or whatever measure of usage you care to employ, of a tramline built in 1920 and operated until 2050 will be a lot lower than one built in 2010 and equivalently operated to 2050. In reality that 1920 tramline will need to have its foundations broken up and relaid a couple of times in its life, and presumably its catenary system would need replacing too. If everything has a life, or some reliable mechanism for charging the player for its age, we can then calculate benchmark infrastructure costs for fulfilling a given transport task, and thus calculate a logical balance between modes. If it doesn't, I don't have any answers yet.
QuoteThe decision of whether or not to purchase, in a commercial organisation that has capital available, is foremost driven by return on capital. The unit could be made by Santa's elves, it doesn't matter, the question investors ask is "what will be the return on my capital?". Don't fixate on how the vehicle is produced or acquired, especially as nothing was genuinely mass-produced before the 20th century. I mentioned before that transport costs have fallen over time - one of the drivers of that has been mass-production of transport equipment, which has reduced capital cost per unit of work, which means revenue per unit of work can fall and return on capital remains constant. You won't get good return on capital buying and operating an 1870's steam engine today, and that has to be the case in the sim. In their day, though, the 1870's steam loco and the 2010 diesel should, under equivalent operating conditions, generate similar return on capital. Return on capital is the simplest, most realistic, and most reliable benchmark that I can see. To deviate from that risks arbitrariness.
Quote from: jamespetts on January 28, 2011, 01:29:10 AMI have split the lengthy discussion about how fast that postman can pedal their bicycles here so that we can concentrate on general balancing discussion here.
Quote from: jamespetts on January 28, 2011, 01:29:10 AMI think that I understand the point: infrastructure, generally, like vehicles needs to be renewed regularly? In other words - its upkeep cost is not static over time, but increases with age? I think that that can probably be simulated, but it's harder than for vehicles. We can't force players to re-lay the tracks every few years, and it's important to avoid players having to micromanage the renewal schedules for each tile (and there's no way of defining sets of tiles without more coding work than I am able to undertake in a reasonable timescale), but I suspect that there may well be a way around this with sufficient abstraction. In any event, implementation can be considered once we have determined that it is a good idea to implement this dynamic in the first place.
Quote from: jamespetts on January 28, 2011, 01:29:10 AMOne point of some significant note, however, is that, whilst tracks, roads, catenary, etc., are regularly renewed, bridges and tunnels, generally, aren't (although they are maintained, of course). Just as it is unrealistic to have roads last forever, so too it is unrealistic to have to replace one's tunnels every so many years (incidentally, how does one account for special infrastructure such as bridges and tunnels when balancing?), so we must account for that aspect of things, too.
Quote from: jamespetts on January 28, 2011, 01:29:10 AMLet me give two historical examples and see whether your model would produce the same results.
Quote from: JamesWould the ROI equalisation model not demand that trolleybuses cost more somewhere to compensate for their advantages?
Quote from: MobletFrom the two examples you've selected, I think you grasp the concepts and trade-offs in ROI, but are perhaps struggling to see how easily they can (and almost currently do) play out in the sim. If one has a faithful model of the dynamics of ROI, then every outcome can be explained in terms of captial vs operating costs, just as you have done here. Capital and operating costs are parameters, and therefore every decision the player makes gets steered by the actual values of the capital vs operating costs. These actual values are something the developers can choose (and, of course, knowledgeable players can manipulate).
QuoteAs you've observed, higher utilisation spreads the infrastructure costs and makes higher-infrastructure, lower operating cost options more attractive. The attached spreadsheet demonstrates this. One can always find a set of assumptions at which either steam or electric is uneconomic, and there is typically a threshold level of utilisation at which the higher capital cost becomes worth it, so it comes down to what one's assumptions and operating conditions are. If the sim is scaled correctly and the relative costs are about right, then the player's trade-offs will look similar to the real world's
QuoteThe player needs to be confronted with parameters that produce a nice trade-off curve, so that if the player electrifies and the line is poorly utilised the player loses money, but if it is highly utilised they make more money than they would have with steam. Note the risk profile here - if you electrify and don't utilise you make a loss, whereas if you don't electrify and highly utilise you don't make a loss, you simply make less profit.
QuoteSteam was still a competitive technology, so Southern would still have made a profit using it, and who knows, maybe they would have made more profit had they done so. Electrification is an obvious point of differentiation, but it wasn't the only contributor to the difference in profitability, and without data of their accounts and operations one couldn't say for certain whether electrification increased or decreased their profitability.
QuoteWe need to find a set of numbers that produces a realistic threshold value, which we can do consciously, and if the sim has ROI or some proxy built into it, the player's outcome will follow the curve.
Quote from: AEOsome of the main reasons to use electric over steam.- better acceleration (good for short station intervals)- climbing ability (no need to use a banking engine)- extensive use inside tunnel- easy to maintain system (not very far from cities or towns)- cleaner to immediate vicinity.
QuoteIt is difficult to simulate a disincentive to make extensive use of steam in tunnels as there is no precise boundary between acceptable and unacceptable levels of usage, particularly as unacceptable levels of usage were tolerated until alternatives were found;
Quote from: sdog on February 01, 2011, 05:42:27 AMYou already have the tool, way restrictions. Introducing a non-steam tunnel (eg. subway tunnel) with lower maintenance costs but a way restriction not to allow steam (and diesel) to use it.