Exploring Park Effects Topic

Some observations...

the rough numbers are saying (stripping out non hit/out PAs) that petco vs Fulton decreases average by 20-25 points, and the constitution of the hits are 1/2 as likely to homer, 2x as likely to triple, and no change in doubles. That last fact is baffling to me...the rest seem to make sense. maybe homers are earlier in the decision tree and the more “non homers” therefore make more hits available to be doubles?

also the fact that petco might be HIGHER xbh/pa shoots some holes in the theory that it’s not worth paying for range in a pitcher’s park
5/17/2020 9:09 AM
Posted by tpistolas on 5/17/2020 9:09:00 AM (view original):
Some observations...

the rough numbers are saying (stripping out non hit/out PAs) that petco vs Fulton decreases average by 20-25 points, and the constitution of the hits are 1/2 as likely to homer, 2x as likely to triple, and no change in doubles. That last fact is baffling to me...the rest seem to make sense. maybe homers are earlier in the decision tree and the more “non homers” therefore make more hits available to be doubles?

also the fact that petco might be HIGHER xbh/pa shoots some holes in the theory that it’s not worth paying for range in a pitcher’s park
Per my understanding, I believe just4me posted about it earlier in this thread, determining whether or not it's a HR is the 1st step in the process.

So, HR <yes or no>, if no <hit or out> if hit <...etc
5/17/2020 10:52 AM
Posted by chargingryno on 5/17/2020 10:52:00 AM (view original):
Posted by tpistolas on 5/17/2020 9:09:00 AM (view original):
Some observations...

the rough numbers are saying (stripping out non hit/out PAs) that petco vs Fulton decreases average by 20-25 points, and the constitution of the hits are 1/2 as likely to homer, 2x as likely to triple, and no change in doubles. That last fact is baffling to me...the rest seem to make sense. maybe homers are earlier in the decision tree and the more “non homers” therefore make more hits available to be doubles?

also the fact that petco might be HIGHER xbh/pa shoots some holes in the theory that it’s not worth paying for range in a pitcher’s park
Per my understanding, I believe just4me posted about it earlier in this thread, determining whether or not it's a HR is the 1st step in the process.

So, HR <yes or no>, if no <hit or out> if hit <...etc
Hit first, then type of hit working backwards with is it a HR, then is a + play, then 3B, then 2B, and finally 1B.
7.0.1
5/17/2020 3:31 PM
bump for RebJebb
5/20/2020 5:10 PM
Posted by contrarian23 on 5/30/2020 11:12:00 PM (view original):
Posted by just4me on 5/9/2020 6:43:00 PM (view original):
Can’t wait to run the end of season #s through the known modifiers and estimates I posted last page. This would help solidify the estimated ranges on some of the factors for AFC and Petco that aren’t specifically known. But so far just eyeballing it, the hit rates and the HR/H, 3B/H, and 1B/H rates seem to support what I posted previously. Would love to maybe run a similar idea again with some constraints on the pitcher ERAs and maybe two parks that have more similar effects with only one area drastically different.
I am hopeful that you will do this and post your results.
I for sure will... and I've been slowly plugging away on that ballpark modifier to the salary sheet, as well. I'll probably use that to help with this. That said, it'll be a few weeks before I can really dig in, big project at work that's been running me some really long work days.
5/31/2020 1:08 AM
Posted by just4me on 4/23/2020 11:59:00 AM (view original):
That last slide would also indicate they don't use a ballpark multiplier for determining singles, just for hits, HR, and 2B/3B...
I asked seble about this today, because I've always believed (just through my own observation) that the 1B rating is for singles. He confirmed that that is the case, and it is not applied to hits in general.
6/2/2020 8:19 PM
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Posted by contrarian23 on 6/3/2020 5:31:00 AM (view original):
That is certainly an interesting statement. I hope seble will clarify, Because that is not consistent with the Paul Bessire presentation that is referenced several times in this thread. If true, that throws open a whole set of questions around the decision tree and the SIM algorithm that run counter to 10+ years worth of discussion on these forums.

Mike, if you are in touch with him, and if he is willing, I would certainly appreciate his comment on the issue as it pertains to the topic of this thread.
I asked seble to follow up because of the apparent discrepancy and linked him to the decision tree presentation and this thread.

after some short back and forths to clarify some things, this was the reply:

Ballpark factors impact singles, doubles, triples, and homers. I can't speak to the accuracy of that presentation because I wasn't even aware of that previously

I think this keeps both interpretations in play, especially with the wording here: "Ballpark factors impact singles, doubles, triples, and homers." Assuming the decision tree still works the way it did when these slides were made, I still am on the side of 1B ballpark modifier modifies hits and then trickles down to "impact" singles. If there were changes to the decision tree, this may not be correct, but given how fatigue still effects BB/H/HR the same as it did when this presentation came out, I don't think the tree has changed.

6/24/2020 3:20 PM
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Posted by just4me on 4/30/2020 12:32:00 PM (view original):

-4 -3 -2 -1 0 +1 +2 +3 +4
1B x x 0.908 x 1.000 x x 1.182
2B 0.795 x x x 1.000 x x x 1.291
3B x 0.523 x x 1.000 x x x 1.868
HR/L 0.634 x x x 1.000 x x x 1.385
HR/R 0.636 x x x 1.000 x x x 1.374
PF 0.820 x x 1.000 x x x 1.370
-4 -3 -2 -1 0 +1 +2 +3 +4
1B 0.816 0.862 0.908 0.954 1.000 1.046 1.092 1.138 1.184
2B 0.800 0.850 0.900 0.950 1.000 1.050 1.100 1.150 1.200
3B 0.400 0.550 0.700 0.850 1.000 1.150 1.300 1.450 1.700
HR/L 0.640 0.760 0.840 0.920 1.000 1.080 1.160 1.240 1.320
HR/R 0.640 0.760 0.840 0.920 1.000 1.080 1.160 1.240 1.320
PF 0.800 0.850 0.900 0.950 1.000 1.050 1.100 1.150 1.200

I'm going to use the same example Paul used in his presentation, then add in the modifiers.

2000 Pedro Martinez vs 1923 Babe Ruth:
[H/AB=((AVG*OAV)/Lgavg)/((AVG*OAV)/LgAVG+(1-AVG)*(1-OAV)/(1-LGAVG))
Where, LgAVG=(PLgAVG+BLgAVG)/2]
Thus: H/AB=((.393*.167)/.2791)/((.393*.167)/.2791+(1-.393)*(1-.167)/(1-.2791))
Where, LgAVG=(.283+.276)/2], or .2791

Log5 result = .2504 This is the expected AVG for Ruth or OAV for Pedro in this matchup including normalization. If they had both been lefties or righties we then would've used the handedness modifier (new result would have been .2379, but that doesn't apply here). So in this case we apply the hit modifier (1B effect). For Coors that's a multiplier of 1.182, and the new result is .2959, for a -3 Park, like Petco, our modifier range is .862-.908, so in a worst case, that would be the original .2504*.862, or .2158. The next step if it is a hit is to determine what type of hit. WIS works backwards and starts with HR. The HR/H rate is calculated the same way as the H/AB but instead of AVG, OAV, LgAVG we use bHR/H, pHR/H, and LHR/H.

Thus: HR/H=((.200*.132)/.0805)/((.200*.132)/.0805+(1-.200)*(1-.132)/(1-.0805))
Where, LgHR/H=(.124+.037)/2], or .0805
Log5 result = .3027 (roughly 30% of the hits Ruth gets off of Pedro will be HRs. Now, in Coors, this wold be multiplied by the HR/RF (Sim assumes pull for hitter in calculations), so we take the .3027 and multiply the HR modifier of 1.374 to get a park adjusted rate of .4159 or roughly 41 HR per 100 hits off of Pedro in Coors.

This is HR/H, not HR/AB. The HR/AB for this matchup is simply multiplying the H/AB rate by the HR/H rate. (.2959*.4159) for a HR/AB of .1230 in Coors. In Petco we'd start with the -3 modifier (which puts us somewhere between .64-.76, so we'll use .7 for our estimate) and multiply the original outcome of .3027 by .7 to get the park adjusted HR/H rate of .2118 or roughly 21 HR per 100 hits or a (.2158*.2118) .0457 HR/AB in Petco (12.3 HR/AB in Coors & 4.57 HR/AB in Petco for this particular Batter/Pitcher matchup (7.58 HR/AB in neutral park)).

If it's not a HR, then using a regression from the pitcher ERA and the batters 3B/H and 2B/H, the SIM works to see if it's a + play on defense , or a triple or double the same as the HR above and uses the park effects the same way. Any hits that didn't become HR, + play, 3B, or 2B are singles.
bumping this for current league discussion around fatigue and decision tree...

Basically the handedness adjustment would be applied against the end result and fatigue is applied against the RL AVG (for a hitter) and OAV (for a pitcher) at the beginning of the equation. By applying fatigue there, it trickles down and impacts all of the hit rate stats for the hitter (HR/H, 3B/H, 2B/H, etc). This works the same way for the pitcher and impacts their HR rate, ERA, etc by applying the fatigue impact at the beginning. Since BB is determined before hit, the fatigue impact is also applied at the BB or non-BB decision before it moves to the hit-out equation.
6/28/2022 10:03 PM
Fantastic discussion here guys and probably why certain guys Win consistently....know the game, know how it works. I wish I did but do not have the time nor the math skills to do the regressions....so I just try and learn a bit at a time from others....its slow but I am always getting better.

Have seen many flaws in the system get exploited then eventually they get addressed (Super Range, Superman Pitching strategy, etc.) but I think the one most frustrating right now to me is the one on allowing early 20th century guys with 350+ IP and 45 starts to be able to appear in 80 games and pitch 5-6 in each one with little penalty. This is WhatIf sports but that too ridiculous, especially coming from a ragarm college pitcher like me...its not possible to be that kind of effective every other day. I once faced 1971 Seaver I think 4 times in a 6 game WS loss. He had 25 IP, 2 ER, 2 CG and little fatigue as a SP then relieved 2IP in last game and got a save. I dont think any human could do that even if in Petco against the worst hitting team in history..hah.

I know they put a little appearance penalty in there or something that kicks in after 12IP within 3 games just think it needs to be juiced a little. Also, think the BB/9 is a bit off but I know it is based on hitter first, vs. pitcher control... just two minor tweaks that I believe would do wonders. Just my flawed thinking.
9/1/2025 10:57 AM
Posted by The_Creeper on 9/1/2025 10:57:00 AM (view original):
Fantastic discussion here guys and probably why certain guys Win consistently....know the game, know how it works. I wish I did but do not have the time nor the math skills to do the regressions....so I just try and learn a bit at a time from others....its slow but I am always getting better.

Have seen many flaws in the system get exploited then eventually they get addressed (Super Range, Superman Pitching strategy, etc.) but I think the one most frustrating right now to me is the one on allowing early 20th century guys with 350+ IP and 45 starts to be able to appear in 80 games and pitch 5-6 in each one with little penalty. This is WhatIf sports but that too ridiculous, especially coming from a ragarm college pitcher like me...its not possible to be that kind of effective every other day. I once faced 1971 Seaver I think 4 times in a 6 game WS loss. He had 25 IP, 2 ER, 2 CG and little fatigue as a SP then relieved 2IP in last game and got a save. I dont think any human could do that even if in Petco against the worst hitting team in history..hah.

I know they put a little appearance penalty in there or something that kicks in after 12IP within 3 games just think it needs to be juiced a little. Also, think the BB/9 is a bit off but I know it is based on hitter first, vs. pitcher control... just two minor tweaks that I believe would do wonders. Just my flawed thinking.
This might help you with the appearance fatigue: https://www.whatifsports.com/forums/Posts.aspx?topicID=523732.

Fascinatingly, though, taking full advantage of this messes you up in the playoffs. The only way to "save" fatigue for the playoffs is to under pitch your pitcher by both appearances and pitches. Come playoffs they automatically get credited with having used 95% of their allotment, so best you can do is have 105% of their allotment for the playoffs. fatigue in the playoffs works the same as in regular season, but is prorated for the number of playoff games as opposed to full season. If your team wins series in less than the maximum number of games, it saves you on fatigue as their fatigue is modeled on a full playoff run. I don't know if the model accounts for leagues with less playoff series or if all account for up to 19 games (If they don't, then players in leagues that go right to the WS would seem to recover faster as they would be in what is considered games 13-19 without having accrued pitches/appearances in games 1-12, so could conceivably bank more - I've not tested or asked about that).
9/1/2025 3:57 PM
Posted by The_Creeper on 9/1/2025 10:44:00 AM (view original):
I just expect Bob Gibson to have a 1.12 ERA everytime I use him.
I cannot figure out why Steve Garvey is NOT the juggernaut he was in real life.
Why Dave Parker never dominates in any league even the 70s themes
Why Barry Bonds never hits close to his RL HRs but most often exceeds his BBs.
Why Babe Ruth can hit 90 Hrs in a high cap league no matter which pitchers are used.

Im sure there are other observations...haha.
I've had some pretty good seasons from Dave Parker. Had him on a couple of ToC winners.

Currently have his '78 season in 2 OLs, in one he's 108G .367 .423 .594 18HR, granted he's playing at Coors, I still have plenty of batters under perform in that stadium. He's in top 5 for MVP.
'78 season again, this time at Target, 104G .319 .377 .517 18HR, not bad for a pitcher's ballpark.
'79 season in a $70M TL, 61G .324 .378 .556 12HR. Currently top 3 for MVP.
9/5/2025 8:14 AM
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