Archive for the ‘Projections’ Category

If anyone is out there (hello? helloooo?), as promised, here are the AL team expected winning percentages and their actual winning percentages, conglomerated over the last 5 years. In case you were waiting with bated breath, as I have been.

Combined results for all five years (AL 2009-2013), in order of the “best” teams to the “worst:”

Team

My WP

Vegas WP

Actual WP

Diff

My Starters

Actual Starters

My Batting

Actual Batting

NYA

.546

.566

.585

.039

98

99

.30

.45

TEX

.538

.546

.558

.020

102

95

.14

.24

OAK

.498

.490

.517

.019

104

101

-.08

.07

LAA

.508

.526

.522

.014

103

106

.07

.17

TBA

.556

.544

.562

.006

100

102

.24

.17

BAL

.460

.452

.463

.003

110

115

-.03

-.27

DET

.548

.547

.550

.002

97

91

.21

.31

BOS

.546

.596

.546

.000

99

98

.26

.36

CHW

.489

.450

.488

-.001

99

97

-.16

-.29

TOR

.479

.482

.478

-.001

106

107

-.05

.12

MIN

.468

.469

.464

-.004

108

109

-.07

-.07

SEA

.462

.464

.446

-.016

106

106

-.26

-.36

KCR

.474

.460

.444

-.030

108

106

-.22

-.28

CLE

.492

.469

.462

-.030

108

109

.13

.01

HOU

.420

.420

.386

-.034

106

109

-.46

-.61

I find this chart quite interesting. As with the NL, it looks to me like the top over-performing teams are managed by stable high-profile, peer and player respected guys – Torre, Washington, Maddon, Scioscia, Leyland, Showalter.

Also, as with the NL teams, much of the differences between my model and the actual results are due to over-regression on my part, especially on offense. Keep in mind that I do include defense and base running in my model, so there may be some similar biases there.

Even after accounting for too much regression, some of the teams completely surprised me with respect to my model. Look at Oakland’s batting. I had them projected as a minus -.08 run per game team and somehow they managed to produce .07 rpg. That’s a huge miss over many players and many years. There has to be something going on there. Perhaps they know a lot more about their young hitters than we (I) do. That extra offense alone accounts for 16 points in WP, almost all of their 19 point over-performance. Even the A’s pitching outdid my projections.

Say what you will about the Yankees, but even though my undershooting their offense cost my model 16 points in WP, they still over-performed by a whopping 39 points, or 6.3 wins per season! I’m sure Rivera had a little to do with that even though my model includes him as closer. Then there’s the Yankee Mystique!

Again, even accounting for my too-aggressive regression, I completely missed the mark with the TOR, CLE, and BAL offense. Amazingly, while the Orioles pitched 5 points in FIP- worse than I projected and .24 runs per game worse on offense, they somehow managed to equal my projection.

Other notable anomalies are the Rangers’ and Tigers’ pitching. Those two starting staffs outdid me by seven and six points in FIP-, respectively, which is around 1/4 run in ERA – 18 points in WP. Texas did indeed win games at a 20 point clip better than I expected, but the Tigers, despite out-pitching my projections by 18 points in WP, AND outhitting me by another 11 points in WP, somehow managed to only win .3 games per season more than I expected. Must be that Leyland (anti-) magic!

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Ok, enough of the bad Posnanski and Woody Allen rants and back to some interesting baseball analysis – sort of. I’m not exactly sure what to make of this, but I think you might find it interesting, especially if you are a fan of a particular team, which I’m pretty sure most of you are.

I went back five years and compared every team’s performance in each and every game to what would be expected based on their lineup that day, their starting pitcher, an estimate of their reliever and pinch hitter usage for that game, as well as the same for their opponent. Basically, I created a win/loss model for every game over the last five years. I didn’t simulate the game as I have done in the past. Instead, I used a theoretical model to estimate mean runs scored for each team, given a real-time projection for all of the relevant players, as well as the run-scoring environment, based on the year, league, and ambient conditions, like the weather and park (among other things).

When I say “real-time” projections, they are actually not up-to-the game projections. They are running projections for the year, updated once per month. So, for the first month of every season, I am using pre-season projections, then for the second month, I am using pre-season projections updated to include the first month’s performance, etc.

For a “sanity check” I am also keeping track of a consensus expectation for each game, as reflected by the Las Vegas line, the closing line at Pinnacle Sports Book, one of the largest and most respected online sports books in the internet betosphere.

The results I will present are the combined numbers for all five years, 2009 to 2013. Basically, you will see something like, “The Royals had an expected 5-year winning% of .487 and this is how they actually performed – .457.” I will present two expected WP actually – one from my models and one from the Vegas line. They should be very similar. What is interesting of course is the amount that the actual WP varies from the expected WP for each team. You can make of those variations what you want. They could be due to random chance, bad expectations for whatever reasons, or poor execution by the teams for whatever reasons.

Keep in mind that the composite expectations for the entire 5-year period are based on the expectation of each and every game. And because those expectation are updated every 6 months by my model and presumably every day by the Vegas model, they reflect the changing expected talent of the team as the season progresses. By that, I mean this: Rather than using a pre-season projection for every player and then applying that to the personnel used or presumed used (in the case of the relievers and pinch hitters) in every game that season, after the first 30 games, for example, those projections are updated and thus reflect to some extent, actual performance that season. For example, last year, pre-season, Roy Halladay might have been expected to have a 3.20 ERA or something like that. After he pitched horribly for a few weeks or months, and it was well-known that he was injured, his expected performance presumably changed in my model as well as in the Vegas model. Again, the Vegas model likely changes every day, whereas my model can only change after each month, or 5 times per season.

Here are the combined results for all five years (NL 2009-2013):

Team

My Model

Vegas

Actual

My Exp. Starting Pitching (RA9-)

Actual Starting Pitching (FIP-)

My Exp. Batting (marginal rpg)

Actual Batting (marginal rpg)

ARI

.496

.495

.486

103

103

0

-.08

ATL

.530

.545

.564

100

97

.25

.21

CHC

.488

.478

.446

103

102

-.09

-17

CIN

.522

.517

.536

104

108

.01

.12

COL

.494

.500

.486

102

96

-.04

-.09

MIA

.493

.472

.453

102

102

.01

-.05

LAD

.524

.526

.542

96

99

.02

-.03

MLW

.519

.509

.504

105

108

.13

.30

NYM

.474

.470

.464

106

108

-.02

.01

PHI

.516

.546

.554

96

98

-.01

.07

PIT

.461

.454

.450

109

111

-.19

-.28

SDP

.469

.463

.483

110

115

-.12

-.26

STL

.532

.554

.558

100

98

.23

.40

SFG

.506

.518

.515

98

102

-.19

-.30

WAS

.497

.484

.486

103

103

.01

.07

If you are an American league fan, you’ll have to wait until Part II. This is a lot of work, guys!

By the way, if you think that the Vegas line is remarkably good, and much better than mine, it is at least partly an illusion. They get to “cheat,” and to some extent they do. I can do the same thing, but I don’t. I am not looking at the expected WP and result of each game and then doing some kind of RMS error to test the accuracy of my model and the Vegas “model” on a game-by-game basis. I am comparing the composite results of each model to the composite W/L results of each team, for the entire 5 years. That probably makes little sense, so here is an example which should explain what I mean by the oddsmakers being able to “cheat,” thus making their composite odds close to the actual odds for the entire 5-year period.

Let’s say that before the season starts Vegas thinks that the Nationals are a .430 team. And let’s say that after 3 months, they were a .550 team. Now, Vegas by all rights should have them as something like a .470 team for the rest of the season – numbers for illustration purposes only – and my model should too, assuming that I started off with .430 as well. And let’s say that the updated expected WP of .470 were perfect and that they went .470 for the second half. Vegas and I would have a composite expected WP of .450 for the season, .430 for the first half and .470 for the second half. The Nationals record would be .510 for the season, and both of our models would look pretty bad.

However, Vegas, to some extent uses a team’s W/L record to-date to set the lines, since that’s what the public does and since Vegas assumes that a team’s W/L record, even over a relatively short period of time, is somewhat indicative of their true talent, which it is of course. After the Nats go .550 for the first half, Vegas can set the second-half odds as .500 rather than .470, even if they think that .470 is truly the best estimate of their performance going forward.

One they do that, their composite expected WP for the season will be (.430 + .500) / 2, or .465, rather than my .450. And even if the .470 were correct, and the Nationals go .470 for the second half, whose composite model is going to look better at the end of the season? Theirs will of course.

If Vegas wanted to look even better for the season, they can set the second half lines to .550, on the average. Even if that is completely wrong, and the team goes .470 over the second half, Vegas will look even better at the end of the season! They will be .490 for the season, I will be .450, and the Nats will have a final W/L percentage of .490! Vegas will look perfect and I will look bad, even though we had the same “wrong” expectation for the first half of the season, and I was right on the money for the second half and they were completely and deliberately wrong. Quite the paradox, huh? So take those Vegas lines with a grain of salt as you compare them to my model and to the final composite records of the teams. I’m not saying that my model is necessarily better than the Vegas model, only that in order to fairly compare them, you would have to take them one game at a time, or always look at each team’s prospective results compared to the Vegas line or my model.

Here is the same table as above, ordered by the difference between my expected w/l percentage and each team’s actual w/l percentage. The firth column is that difference. Call those differences whatever you want – luck, team “efficiency,” good or bad managing, player development, team chemistry, etc. I hope you find these numbers as interesting as I do!

Combined results for all five years (NL 2009-2013), in order of the “best” teams to the “worst:”

Team

My Model

Vegas

Actual

Difference

My Exp. Starting Pitching (RA9-)

Actual Starting Pitching (FIP-)

My Exp. Batting (marginal rpg)

Actual Batting (marginal rpg)

PHI

.516

.546

.554

.038

96

98

-.01

.07

ATL

.530

.545

.564

.034

100

97

.25

.21

STL

.532

.554

.558

.026

100

98

.23

.40

LAD

.524

.526

.542

.018

96

99

.02

-.03

SDP

.469

.463

.483

.014

110

115

-.12

-.26

CIN

.522

.517

.536

.014

104

108

.01

.12

SFG

.506

.518

.515

.009

98

102

-.19

-.30

COL

.494

.500

.486

-.008

102

96

-.04

-.09

NYM

.474

.470

.464

-.010

106

108

-.02

.01

PIT

.461

.454

.450

-.010

109

111

-.19

-.28

ARI

.496

.495

.486

-.010

103

103

0

-.08

WAS

.497

.484

.486

-.011

103

103

.01

.07

MLW

.519

.509

.504

-.015

105

108

.13

.30

MIA

.493

.472

.453

-.040

102

102

.01

-.05

CHC

.488

.478

.446

-.042

103

102

-.09

-.17

As you can see from either chart, it appears as if my model over-regresses both batting and starting pitching, especially the former.

Also, a quick and random observation from the above chart – it may mean absolutely nothing. It seems as though those top teams, most of them at least, have had notable, long-term, “players’ managers,” like Manuel, LaRussa, Mattingly, Torre, Black, Bochy, and Baker, while you might not be able to even recall or name most of the managers of the teams at the bottom. It will be interesting to see if the American League teams evince a similar pattern.