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Run_Win_Expectancy
Wednesday, October 08, 2008
Now this is cool. Forget Dan Rather, Keith Olbermann, and whoever else Nate has met. Stephen Colbert? Guest-speaker to the President’s dinner? Wittiest man in America? A one-time presidential candidate? That’s really cool. Nate looked nervous, unlike his very calm demeanor with the other guys. Must be tough to be sparring with a comedian as sharp as Colbert. Colbert was pretty good to Nate. Nate had one good line where he tried to put a baseball analogy to the race for presidency, likening Obama to the Rays, that we’re in the 9th inning down by 2, and Palin was just picked off first base. Must feel great to make a funny guy like Colbert laugh.
Nate has Obama with an 89% win expectancy as of today. Bottom of the 9th, 1 out, down by 2 is a 96% chance of winning. Down by one though is a 90% chance. So, that’s where we are in the race. Bottom of the 9th, 1 out, down by 1 run, McCain batting, Obama pitching.
Thursday, October 02, 2008
Here is my first stab at trying to describe Situational Wins. Please provide comments, especially as it pertains to readability. I will then make the necessary modifications, and I’ll submit it to THT for publication for the general public to consume.
Saturday, September 20, 2008
I posted this at Primer:
I’m not discussing whether WPA/LI is appropriate or not for Cy Young (I would lean toward not). I’m asking a more general question about what Balrick thinks that WPA/LI is trying to do.
***
Thank to fret for bringing up that game.
In that particular inning, the WPA totaled -.049 wins. Indeed, every scoreless top of the half will give the defense -.049 wins in WPA, regardless whether you had 3 or 6 batters. People who like just runs like that. Those who care about number of runners allowed don’t.
WPA/LI for the game in question for the top of the 1st was +.019. (Plus is bad for the defense.) What WPA/LI does is treat each PA in isolation, unleverages WPA so that it scales the performance so that each PA is weighted at exactly 1.0, and weights each event (walk, homer, strikeout, etc) with respect to the game state (e.g., K are more impactful with runner on 3b and less than 2 outs than otherwise).
Is it necessarily a bad thing that a team that allows 2 runners out of 4 batter to reach base to show that they are below average (even though they got out of the inning scoreless)? I don’t think it’s necessarily a bad thing. I don’t know that it’s necessarily a good thing.
But to dismiss WPA/LI would be preferable with reasoning behind it.
WPA/LI is exactly perfect for a hitter, if you believe that it matters when a hitter strikes out with runner on 3B and less than 2 outs, and you don’t think that it’s just another out. That is, you believe that the batter and pitcher realize that that situation requires a fairly strong change in approach. Only WPA/LI will give you what you need, under this belief premise. Linear Weights by the 24 base/out states is a close second.
WPA/LI is not as good for a pitcher, since a pitcher is his own team, and each PA should not necessarily be treated as if they are as impactful as any other PA. WPA/LI forces each PA to be worth exactly 1.0.
Monday, September 08, 2008
UPDATE: This post has been corrected due to a bug on my part.
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Great job by Zach, but I’ll quibble on the conclusion:
What’s funny is that Clay Davenport, inventor of Pythagenport, denounced his method in favor of Pythagenpat, yet it is in reality the best method when compared to actual record.
When the RMSE of one is 3.990 and from another is 3.992, that is essentially a tie. What I did is repeated Zach’s study, with a wrinkle of my own. Through 2007, he has 1792 team-seasons in his study. I figured out the Clay and Pat win%, which I then multiplied by W+L, and then rounded to the closest whole number to get a win estimate.
The results. Out of those 1792 team-seasons, there was a tie 1713 times! In the other 79 times, Clay did better 39 times and Patriot was 40. If we give each of them half-wins for their ties, Clay’s head-to-head win% over Patriot is .4997. What works in Patriot’s favor is that it is a simpler construction that doesn’t break down at the extremes.
It’s fair enough to say that they are both equals for the sample at hand (where most teams play in a 9-10 runs per game environment), while Patriot won’t break down at the extreme levels.
Friday, August 15, 2008
Adam Dunn is what WPA/LI was invented for. In 4500 PA, his wins added over an average hitter, given the base/out inning/score opportunities presented to him was +18 wins.
The most similar player to Adam Dunn in terms of OBP, SLG, and PA is JD Drew. In his career, Drew is +25 wins.
Three other players with less PA are: Teixeira (+12 situational wins), Bay (+14 wins), and Miguel Cabrera (+20 wins). If you add up their totals (+46) to Drew’s (+25), and take 30% (to align them to the same number of PA as Dunn), you get +21 wins.
I think there may be something to the fact that Dunn is not a good situational hitter (or that his skillset doesn’t lend itself to good situational hitting).
He’d definitely be a good case study.
Here is the comparison line, as of today:
+18 situational wins, .247 / .380 / .519 Dunn
+21 situational wins, .290 / .382 / .522 Dunn’s top 4 comps (Tex, JD, Miguel, Bay)… situational wins prorated to Dunn’s PA.
Monday, August 11, 2008
Your reliever gets an out. Your chances of winning go up. Your reliever allows a runner on. Your chances of winning go down. You add up the deltas of all the times that your chances went up, and you add up all the deltas of all the times your chances went down. Call the former “Win Advancement” (WA) and call the latter “Loss Advancement” (LA). WA+LA is GA (Game Advancement).
If you start the game at zero, you are marching toward 1 Win or 1 Loss. In a typical win, the pitching team will accumulate 1.8 WA and 0.8 LA. The difference in WA and LA, for every win, is always 1.0. Always. That is, on your march toward a win, you’ll accumulate some good things and some bad things. And in a win, you’ll accumulate alot more good things than bad things. The difference, in a win, will always be +1. Similarly, in a typical loss, the pitching team will accumulate 0.8 WA and 1.8 LA, with the difference always being -1.
So, in an average game, you have 1.3 WA, 1.3 LA, 0.5 wins, and 0.5 losses. The WA and LA capture the ebb and flow of the game, on your march toward the win or loss of the game. There is, on average, some 0.8 “wasted” WA and 0.8 “wasted” LA per game (2.6 GA minus 1 game). In order to align WA and LA to W and L, simply subtract the waste (average of 0.8 wasted advancements on each side) from the total accumulation in each game (average of 2.6 GA) from each of WA and LA.
Before we talk about relievers, let’s look at the last generation’s four greatest starters:
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Wednesday, August 06, 2008
Leaderboards as of this morning on Fangraphs:
WPA: Batters
Lance Berkman 5.29
Pat Burrell 4.98
Albert Pujols 4.47
Jason Bay 4.42
Manny Ramirez 4.18
Ramirez is also #7 in WPA/LI and Bay is #9.
That is all.
Thursday, July 31, 2008
I know I talked about this here at some point. It came up again in the Mailbag, and wanted to draw your attention to my rather lengthy and technical response.
Wednesday, July 23, 2008
Bill James posted Mariano’s seasonal Win Shares - Loss Shares, whereby he gives him a total of 136 Win Shares and 24 Loss Shares. I replied:
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Monday, July 14, 2008
Regression analysis is sabermetrics is probably the worst thing that has happened to its discipline. Rather than it being treated as a starting point, it’s treated as the target point. Even smart learned men make this goof. Nowhere is it more evident than in the regression run value of a double, as Patriot shows us here:
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Thursday, July 10, 2008
What WPA represents is the quantification of your feelings as the game unfolds. Imagine if Youk hit into a triple play his first 2 AB, with the score tied 0-0 the whole time, then the Sox lead 15-0 (and he gets two outs), then he hits two HR. How is it that you felt with Youk, if you tracked it in real time?
Well, his first two AB, you are cursing his name like there’s no tomorrow, then when the team batted around (twice), your blood pressure starts to go down, and then, with the score at 15-0, you’re probably not even watching the game any more.
That is what WPA captures.... the quantification of your feelings as the game unfolds, assigned to the players involved.
WPA is not a way to evaluate the talent of a player. WPA is exactly the same as counting a PA 11 times when the bases loaded down by 1 with 2 outs in the bottom of the 9th and counting a PA as almost zero in a blowout game. It is basically ridiculous to think that one PA can inform you on the talent level of a player 1000 times more in one situation than another.
WPA/LI however might be a way to evaluate the talent of a player, since now each PA is exactly worth 1 PA. The only thing we are doing is realizing that baseball might not be a random game, and that a player might tailor his approach based on the base/out inning/score. We don’t know how much he does tailor his approach. That needs to be studied.
Tuesday, June 17, 2008
Referencing this article on VORP, some BTF readers make some curious statements, while JC makes some puzzling ones.
I made this post at both blogs:
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Saturday, June 14, 2008
By , 06:16 PM
In the bottom of the 10th inning in today’s BOS game, CIN was down by 2 runs with 2 outs, with Jolbert Cabrera, a veteran journeyman player, on second base. With Griffey on base and the shift on, Jolbert easily took third on the next pitch, since no one was playing near third base.
Now, obviously being on third base is no better than being on second in that situation. In fact, you can make an argument that a foul ball occasionally hits a runner on third in fair territory, so that it is better to be on second, although I don’t think I’ve ever seen that, and it is exceedingly rare (if it has ever happened at all). Plus, being on second base, you can possibly steal the signs or the location and relay it to the batter, although runners rarely if ever do that anymore (I am not sure why). On the other hand (that is the last hand, I think), being on second might be a distraction to the batter, although certainly you are not going to be “jockeying” on the basepaths and you certainly don’t need to have any kind of a lead since it doesn’t matter if you score on a hit.
Now, even if he can walk to third on the pitch, which was apparently the case, there is a non-zero chance that you could trip and fall and get thrown out. I found it curious that a guy who has been playing baseball for almost 30 years would do that (take third).
Thursday, June 12, 2008
RE chart for the entirety of Retrosheet years.
To read the first record: with the bases empty and 0 outs, there have been almost 2 million PA with almost 1 million runs scoring from that point to the end of the inning. The average (R/PA) is 0.494 runs, which is labeled as REOI (runs to end of inning). REOI_0 is the percentage of times that there were no runs scored at all in that inning (72.7% in this case).
Excluded are all partial innings, and home halves of 9th and later innings. I am only looking at the base/out state at the start of the PA.
Here’s the SQL
Friday, June 06, 2008
I don’t know when THT rolled out Fangraphs WPA stats, but I like it. They give you the team-level totals. The Angels for example are a total of +6.5 wins (meaning their actual wins minus losses is 13 games… as you can see, the player performances are a perfect match to their teams’ record). That breaks down as -2.0 wins for batting, +4.7 for starters, and +3.7 for relievers.
Fangraphs is likely using a run environment that is too high, meaning it gives too much credit to pitchers. The total for the 30 MLB teams should have batting as exactly 0.0 and starters+relievers as exactly 0.0. Checking now… the total of the 30 MLB teams is -51 wins on offense and obviously +51 on pitching. So, until David A. updated the run environment charts he uses for the win expectancies, you need to mentally add +51 wins per 70,000 or so PA to your hitters (i.e., about +0.1 wins per 200 PA), and remove 51 wins per 16,000 or so IP to your pitchers (about -0.2 wins per 70IP). As you can see, no big deal at the player level so far.
Also note that starters are way behind relievers, as they always are. Relievers get the advantage in that their run environment is being compared against a fixed point (say 4.50 runs per game), when in fact relievers, because they are relievers, should actually be compared to a lower run environment. But, the charts I provided David doesn’t allow for that to be handled. I can do it, but it’s a pain in the butt.
In any case, since you likely want to compare to replacement level, not average, you’ll have to make an adjustment anyway, so you might as well do it after-the-fact, and not in real-time.
Anyway, the reason I happen to discover THT’s WPA charts, is that Rally was talking about the Mariners fielding. It seems that Safeco is always at the center of issues with fielding stats. They’ve got close to the league-low in both infield and outfield fielding. It’s hard to believe that a team with Beltre and Betancourt and Ichiro can be that dismal. Either the other players are so dreadful as to bring them all down, or one or all of these guys aren’t as good as their reps.
At some point, I’ll be looking at Safeco’s PBP data to see if there’s something strange with their data.
Wednesday, May 21, 2008
Fangraphs is showing the average LI and average win expectancy for each game for a particular day in its sidebar (sorted for your ease). So, you can see which game is the most “exciting” based on these two measures (high LI means alot of swing potential, and a win expectancy that is close to .500 probably means that the game was close for a good part of the game).
Thursday, May 08, 2008
Guy has it right when he says:
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Wednesday, April 23, 2008
Fangraphs is starting to add the years, and 1974 was the first one. John Lowenstein and Tommy Hutton are your clutch hitters that year, while Yaz was the choker of the year. The leader in Leverage Index was Tom Murphy (who?) at 2.05. He also happened to be the best reliever that year. So, the Brewers used him perfectly.
Friday, April 18, 2008
Smart people make this mistake all the time, but friend-of-The-Book Joe Sheehan doesn’t:
...with a runner on second and no one out, you have a 62.5% chance of scoring one run. With a runner on third and no one out, you have an 82.7% chance of scoring one run. With one out and no one on, you have a 16.5% chance of scoring one run
He references BBTN, and we have it in The Book as well, but, I’ve also got it online right here. While he did say “one run”, he really meant “at least one run” and not “exactly one run”. And his numbers bear that out. And he was right to compute it that way. With one out and no one on, the chance of scoring exactly one run is 10%. But, the chance of not scoring at all is 83%, meaning the chance of scoring at least one run is 17%. And that is the number we care about. Invariably, we almost always want to know chance of scoring not at all, or its complement. (His 82.7% for runner on 3B looks mighty low. I have it at 86.4 for 1999-2002. Did he mean to say 87.2%?)
Good job to Joe in not falling into the trap. Admiral Ackbar has snagged many a fine folk.
Thursday, April 17, 2008
Studes has a little program as to how to calculate WPA Above Baseline. He actually taught himself PHP so that we have a simple calculator. Sweet. I think the algorithm needs modification though. He says:
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