An Introduction to the SR System

Almost six years from this thread and SR is still being one of the main topics. Dennis Grebe wrote this introductory guide to the Safety rating system to give a few hints about how to bypass its importance.

There has been a lot of confusion, misunderstanding and in most cases simply a lack of knowledge about the SR system. I collected answers to questions that came up in the last three to four months, put them together and sorted them from basic to more advanced/complicated.

Here’s the quick and dirty run down of what you probably should know about the SR system:

  • To advance to a higher license, you will have to improve your Safety Rating. The Safety Rating is the only consideration for the license levels. When you have reached a higher license you can lose it again and get demoted if your Safety Rating sinks too much.
  • Safety Rating is a measure of safety in sessions (Qualifying, Warmup, Race [official and unofficial] and Time Trials). It only takes into account the amount of incident you have for the the amount of corners you have driven through. For the Safety Rating, your qualifying or finishing position do not matter at all. When you drive safely, don’t have any incidents and finish last you will be better off than having incidents and finishing first. At least as far as your Safety Rating is concerned.
  • You have two SR ratings, one for Ovals and one for Road. The category a race falls into is determined by the class of the series ONLY. When the Star Mazda Series visits an Oval (in 2011-1 that would be Richmond Night for example) it still counts towards your Road SR. You can (and will) advance your road and oval licenses seperately. To achieve Oval C you don’t need to achieve Road C at the same time. You could be a Pro in Oval but a Rookie in Road.
  • Road and Oval SR are no longer linked. They were before the 2/2/2010 build but are no longer. You run oval, it stays in oval. You run road, it stays in road. (Thanks Stephen!)
  • There are four levels of incidents: 0x (light contact with the wall OR light contact with another car), 1x (off track), 2x (hard contact with wall OR lost control) and 4x (hard/critical contact with another car).
  • The relevant criterion for a 1x off track is the geometric center of the car. You get the 1x if it moves over an illegal track material. Usually anything within the white lines and (at least) the first line of curbing is legal. What is considered legal and illegal, especially several lines of curbing in the same spot, can differ between tracks so make sure to test which lines are considered ok in practice.
  • You can “inherit” incident points. If you hit another car for a 0x and the other drivers goes off track (collecting a 2x) you will inherit his 2x and get 2x instead of the 0x. As long as the “0x Incident” message at the top of your screen is showing you can inherit points. That’s for approximately four seconds.
  • The Safety Rating is not a tool to penalize you. It is a tool to quantify (make measurable) the “safeness” of a driver. It counts incident points, nothing more. It does not assess blame. It only allows to see which driver has accrued which level of incident points. In the license system, the higher your SR, the higher the class and series you will be allowed to drive in.
  • While your Safety Rating is calculated from the average of how many corners you go per incident (Corners per Incident, CPI), it is automatically translated into an easier-to-grasp number that is being displayed to you. This will be a number between 1.00 and 4.99.
  • When you cross any x.00 SR-level, you will get an additional 0.40 boost. If you were 2.99 before a race and gained 0.02 by racing, it would put you at 3.01 after the race. However since you crossed the x.00 threshold, your new SR will be 3.41. This also works the other way around, when you go from 3.01 to 2.99, the 0.40 you were lent when going up will be detracted again and you will end up at 2.59.
  • When you move up a license level, your SR Rating will generally drop by 1.00. If you were C-4.50 before being promoted to B, you will then be B-3.50.
  • A higher license level will not hurt you. Any car that you want to drive requires just a minimum license. If you want to drive a D-class car like the Skippy, having an A-class license doesn’t hinder you. Promoting to a license higher than the one you need can help you build up a buffer against getting demoted below the level you need to run your desired series however.
  • You can not get demoted back to Rookie. D-Class is the lowest license level available once you exit the Rookie ranks.
  • It’s easier to gain SR in longer races. More corners means better CPI if you keep the number of incidents the same.
  • Once you reach 4.99 in any license class, your SR will seemingly not advance anymore. Your CPI however still does. Should you advance a license level or have a few bad races you will still benefit from the invisible “buffer” above 4.99 you have accrued.
  • When you reach an SR rating of 4.00 or over, you will be immediately promoted to the next higher level if you have met the Minimum Participation Requirements (4 races or 4 time trials in a car of at least the license level of your current license). This is called FastTrack.
  • FastTrack also works the other way around. If your reach an SR rating of below 1.00, you will be immediately demoted to a lower license level.
  • To race in a certain series you need to meet the minimum license requirement.
  • If you have a SR of between 3.00 and 4.00 and met the MPR, you will be promoted at the end of a season. If you have an SR of below 2.00, you will be demoted at the end of a season. This is the regular promotion mechanism.
  • The higher your license, the slower your SR progress will seem to be. The largest part of this is simply because you already have a high Corners per Incident average. The higher your average is, the harder it is to keep improving it. If you’ve written just D’s in your exams, it’ll be easier to improve by writing a C or better. When you’ve already been getting A’s, it’s a lot harder to improve on that. The translation of CPI into the SR value also flattens a bit the higher you move up (see the link to Mathieu’s graphs at the bottom for details).
  • This also means it’s generally easier to lose SR at higher levels because your average is already relatively high. If you’re still in Rookie, a race with with 6 incidents in 10 laps at Lime Rock will likely mean you’ll improve your SR, because it means you achieved a higher CPI-average than you had before. If you’re already in the A license level, 6 incidents in 10 laps at Lime Rock will mean you’ll lose some SR, because it’s worse than your prior average. You’ll however still have a vastly higher SR than the aforementioned Rookie.
  • Your CPI is calculated for a limited history of corners. The exact number of corners taken into consideration is not known to me, but the general assumption is that for a Pro license there are 2600 corners taken into consideration. For lower licenses the number is lower. This means that laps in which you had a lot of incidents will sooner or later drop completely out of your CPI calculation.
  • If you finish with 0 incidents, you will always gain SR. This is because the mechanism of a “weighted moving average” is used to calculated your CPI value. Recent corners (with or without incidents) count more, those towards the end of your history from 10 or so races ago count less. So if you add only clean corners to the front of your history, every incident in your history will be pushed further towards the end and count less, which will make you gain SR even if you did not drop any incidents from your history.
  • A very bad race with lots of incidents will be moderated through two mechanisms: One is the CPI history of a maximum of 2600 corners, so if you don’t follow it up with races that are just as bad, your SR will correct itself soon enough. Two, the CPI is an average over an amount of corners. So your bad race will drop the average but will do so much less than if only the last three races were taken into account.
  • You practically can’t compare SR gains/losses between two drivers. You would need to know the exact CPI history of both drivers for instance. Without knowing the exact history, one driver will drop different corners from the SR calculation than the other.

“Why is it harder to gain SR/easier to lose SR at higher license levels?” – The biggest part of this is that it’s harder to maintain a high average than it is to maintain a low average. To maintain a CPI of 25, you only need a CPI of, well, 25. That’s quite some incidents in a race you can accrue and still come out with a +/-0 to your SR at the end of a race. You also have a lot of room to improve (and thus a chance to improve by a bigger margin) at lower levels, while at the higher license levels you can not improve as much because you already need a low incident count just to keep your current CPI average.

“I had a 0 inc race but my SR dropped” – There’s two likely scenarios here: a) you had incidents in warmup. They count too and they matter for the end-of-race SR change but show in the warmup times table at the bottom of the results page, not the race results table. b) you had incidents in incomplete in-/out-laps. It has been observed that those at times will not show in the final results page. So be careful even after you have crossed the finish line!

They’re called “incidents” for a reason. It’s not “accidents caused” but “incidents”. I’m not a native speaker so you probably get the idea difference immediately but for me and everyone else: Going off track into the grass to avoid a pile up on the track is still an incident. This example also make clear how innocent the implications of an incident are. You can’t tell if it was a “good” incident to avoid a bigger mess or a “bad” incident where you caused havoc by driving erratically into T1 and wiping out half the field. It’s only an incident, nothing more at that point.

When you run off track for what would normally be a 1x, it won’t be an incident if you manage to reduce your speed to below 30mph/50kph before going off track. This can be especially handy when the track in front of you is blocked by spun/crashed cars. (Thanks Michael!)

Some strategies:

  • “If you give a Pro quality driver a D license he’ll be a Pro again in 10 races. If you give D quality driver a Pro license he’ll be a D driver again in 10 days.” Lincoln Miner
    This captures the essence of the averaging system. It takes some time to form an accurate average but in the end you’ll get there. While you’re still moving through the ranks quickly you won’t have reached it just yet. When you have been “stuck” in a certain SR range for several races you probably hit your current safety rating pretty accurately. In all likelihood your SR will always be in flux though, as you have good and bad races while the average of those is somewhere in between. On top of that you’ll always be learning and improving your avoidance skills, or alternatively have a bad day when your reactions aren’t up to the usual standard.
  • Dave Kaemmer suggested in his blog post a simple 2-3-4 rule of thumb: When you’re in the 2.xx range, you should concentrate on being safer. When you’re in the 3.xx range, you’re doing okay and if you’re in the 4.xx range, you should concentrate on going faster. I don’t quite agree with the recommendation for the 4.xx range but the general principle is right: You don’t have to be at 4.99 to be safe. Some incidents just happen from time to time, like the occasional off-track for a 1x, and will cause your SR to fluctuate. If you can keep it cleanly above A-3.00 you’re doing okay. If you’re above A-4.00 you’re doing reasonably good on the safety side. It doesn’t say much about your speed though. Dale Earnhardt Jr. is the second best driver in the oval side by iRating and has a Pro-4.99 SR. Jeff Bye Jr., the leading oval driver by iRating, has a Pro-4.18 (2010/3/16) safety rating. On the road side, Greger Huttu stands at Pro-4.99 and being the fourth highest rated driver by iRating. The three guys in front of him, Rietveld, Hackmann and Towler, stand at A-4.99, A-3.51 and Pro-3.56 respectively. You can be fast and still be safe, there is no conflict between the two.

Interesting Links:

Leave a Reply