Drivers2 Ratings Test

[JR82]

Some more finidings - this time again related to the track's .txt file.  Maybe this thread is more accurately named "AI Performance"

RELS does not get applied in qualifying the way it should / the way it does during the race.

Here's how the qualifying speeds of a base AI car change when RELS  changes (this is at Mich2000)

100% - 239.554
75% - 234.192
50% - 229.065

When adjusting the in-game opponent "strength" value, though - it gets applied the way you would think:

80% - 188.201

It's slightly off (e.g., slightly lower than 80% of the 100% value), but its pretty close.


I verified its the same, even on a road/street course and a base Papy track.  This is for the base Detroit circuit
100% - 1:14.569
50% - 1:17.983.

I verified that race pace was applied the way you expect: e.g,. at 50%, lap times were twice what they were at 100%.

I'm trying to tune circuit AI performance so that at 100% AI strength, you get performance very close to real world lap times, and this unfortunately makes that process significantly more annoying.

---

One more - I was trying to play around with the SPDWY values to see if I could create AI that would use different pit strategies, but unfortunately the AI pitting behavior seems very simple.

AI will simply take a random value in the pit range and use that value for the length of their sting (under green flag conditions).

However, some interesting things I found:

* Pace increases over the course of a stint, but it appears to be a pretty simple linear trajectory.  I was hoping a longer stint might affect the performance in some way (e.g., tires falling off or something), but its not the case.  It seems to be a pretty simple trajectory of starting pace at a full fuel tank down to end pace on an empty tank.  This is true on both road/street courses and ovals.

* However, AI does fill its fuel tank intelligently, and knows how long the stint is they are planning to run.  In my test, I was running a single AI at Road America with a wide pit window (1-20 laps).  And on some occasions, lap times would be close to "full tank" right after a pit, and the AI would run a long stint, while other times they would come out doing "empty tank" lap times and pit a few laps later.

* While AI can intelligently choose a fuel load, it cannot intelligently choose its stint length.  Even if the pit window extends past the end of the race, the AI will not choose the longer stint in order to ensure they don't have to pit again, which is a shame.  E.g., pitting with 15 laps left and the above defined, window, still saw them use a 5-lap stint instead of choosing the longer one that would reach the end of the race.

* However, they do appear to fill fuel only to cover remaining laps, even if "chosen" stint would be longer.  E.g., At Road America set stint length to 16, they pit with two laps left but do a "splash and go" stop rather than put on a full tank.

I could be well off the mark here but re: realistic laptimes, i thought the "BLap" line was an ave laptime across the field with faster cars beating that time & slower cars going slower (gaps dependent on the value gaps u have with the drivers ratings with power/grip etc) and the "Rels" line is a % of the "BLap" time u have set.

[JoyfulPanda]

Some more finidings - this time again related to the track's .txt file.  Maybe this thread is more accurately named "AI Performance"

RELS does not get applied in qualifying the way it should / the way it does during the race.

Here's how the qualifying speeds of a base AI car change when RELS  changes (this is at Mich2000)

100% - 239.554
75% - 234.192
50% - 229.065

When adjusting the in-game opponent "strength" value, though - it gets applied the way you would think:

80% - 188.201

It's slightly off (e.g., slightly lower than 80% of the 100% value), but its pretty close.


I verified its the same, even on a road/street course and a base Papy track.  This is for the base Detroit circuit
100% - 1:14.569
50% - 1:17.983.

I verified that race pace was applied the way you expect: e.g,. at 50%, lap times were twice what they were at 100%.

I'm trying to tune circuit AI performance so that at 100% AI strength, you get performance very close to real world lap times, and this unfortunately makes that process significantly more annoying.

---

One more - I was trying to play around with the SPDWY values to see if I could create AI that would use different pit strategies, but unfortunately the AI pitting behavior seems very simple.

AI will simply take a random value in the pit range and use that value for the length of their sting (under green flag conditions).

However, some interesting things I found:

* Pace increases over the course of a stint, but it appears to be a pretty simple linear trajectory.  I was hoping a longer stint might affect the performance in some way (e.g., tires falling off or something), but its not the case.  It seems to be a pretty simple trajectory of starting pace at a full fuel tank down to end pace on an empty tank.  This is true on both road/street courses and ovals.

* However, AI does fill its fuel tank intelligently, and knows how long the stint is they are planning to run.  In my test, I was running a single AI at Road America with a wide pit window (1-20 laps).  And on some occasions, lap times would be close to "full tank" right after a pit, and the AI would run a long stint, while other times they would come out doing "empty tank" lap times and pit a few laps later.

* While AI can intelligently choose a fuel load, it cannot intelligently choose its stint length.  Even if the pit window extends past the end of the race, the AI will not choose the longer stint in order to ensure they don't have to pit again, which is a shame.  E.g., pitting with 15 laps left and the above defined, window, still saw them use a 5-lap stint instead of choosing the longer one that would reach the end of the race.

* However, they do appear to fill fuel only to cover remaining laps, even if "chosen" stint would be longer.  E.g., At Road America set stint length to 16, they pit with two laps left but do a "splash and go" stop rather than put on a full tank.

I could be well off the mark here but re: realistic laptimes, i thought the "BLap" line was an ave laptime across the field with faster cars beating that time & slower cars going slower (gaps dependent on the value gaps u have with the drivers ratings with power/grip etc) and the "Rels" line is a % of the "BLap" time u have set.

I did test to see if the middle of the field would put in the same times if they were at 500/500/500 vs like 200/200/200 - but it does not appear to be the case.  It seems everything is based on the 500/500/500 values.  And it has zero effect on actual pace of the cars when they're running live.

RELS does have a small impact on BLAP, but like I mentioned I tested this quite thorougly.  99 RELS will give 500/500/500 qualifying times of 99.91% of the BLAP.   The impact on live AI is as you would expect - where 90 RELS will mean 90% pace.

I'm testing these through repeated actual observations in an ICR2 instance and I'm confident in my findings about these at least.

[JR82]

As a matter of interest, are there any further findings/updates from here? Recommended pit window for each track type etc?

[samsepi0l]

Recommended pit window for each track type etc?

I set this by driving by myself and seeing how many laps I can complete on 40 gallons. For example, I just did Laguna Seca (Pavels 90's version) and I completed 27 laps on 40 gallons consistently. Therefore I set the pit window from 25 to 29, which was +/- 2.

[jxeboy]

I used to make quite a wide pit window to make 'strategy' more interesting, however it can lead to cars pitting additional times if they pit on the extreme ends of the window. The default tracks in ICR2 typically have a 2 or 3 lap pit window and i've found this is what works best to make the race as competitive as possible.

I usually set the first number to be one lap less than I think I can make on a tank of fuel, and the higher number to be one lap more than I can do on a tank of fuel.

[samsepi0l]

I used to make quite a wide pit window to make 'strategy' more interesting, however it can lead to cars pitting additional times if they pit on the extreme ends of the window.

At my 1990 Season race in Nazareth a couple of weeks ago, this really screwed Rahal. He pit at a yellow kind of off stint and he had to stop a 3rd time. It was really cool. He was the fastest but the extra stop gave Mears the win.