Sharing the blame

David Berri, who authored the book Wages of Wins and writes the Wages of Wins Journal,
asked me the other day how well we could have expected the Tigers to perform this year given what the players did last year. He also wanted to know which players are underperforming and by how much. There is no definitive answer to these questions but one approach is Win Shares.

Bill James developed Win Shares as a way to estimate the number of wins a player contributes to a team based on his individual statistics. In the Win Shares approach, everything a player does (hitting, fielding, base running and pitching) is summarized with one number. Each win is worth three win Shares. For example, a player with 30 Win Shares is considered to have contributed 10 wins to his team.

The algorithm for determining Win Shares is much too complicated to be detailed here. If you want to learn more, you can read Win Shares written by Bill James and Jim Henzler and published by STATS, Inc. If you want a much briefer version, you can go to Baseball Graphs
The win shares algorithm has been critiqued and altered over the year and these changes are described at The Hardball Times.

I obtained the 2007 and 2008 Win shares statistics from The Hardball Times. THBT updates the win shares every couple of weeks and I thank Dave Studeman for running them the same day I told him I was hoping to use them in this article. Table 1 shows the win shares for batters in 2007 versus 2008. Basically, I calculated expected win shares for 2008 based on 2007 win shares and expected plate appearances in 2008. Using Miguel Cabrera as an example, here is how to read the table:

PA = 680 plate appearances in 2007
WS= 30 win shares in 2007

EPA= 700 expected plate appearances in 2008. This was done mostly to account for acquisitions made during the off-season. You would not, for example, expect Brandon Inge to have the same number of appearances in 2008 as a part-time player as he had in 2007 as a full-time player. Consequently, you would also not expect him to have as many win shares.

EWS=31 expected win shares in 2008 given 2007 win shares and EPA in 2008.

WS=6 win shares in 2008 as of June 5.

PWS= 17 projected win shares in 2008. This is calculated by simple extrapolation assuming Cabrera will perform the same way all season as he did through June 5.

WS diff= PWS-EWS

W diff= WS diff/3 because each win is worth 3 win shares.

Table 2 is similar to table 2 except it presents win shares for pitchers and uses innings pitched to determine expected win shares.


Table 1: Win Shares for Tigers batters - 2007 vs 2008

	2007				2008		2008 - 2007
Player	PA	WS	EPA	EWS	WS	PWS	WS diff	W diff
Granderson	676	26	650	25	3	8	-17	-5.67
Jones	495	15	500	15	0	0	-15	-5.00
Cabrera	680	30	700	31	6	17	-14	-4.67
Ordonez	679	36	650	34	8	22	-12	-4.00
Sheffield	593	16	500	13	1	3	-10	-3.33
Renteria	543	18	600	20	4	11	-9	-3.00
Polanco	641	23	600	22	6	17	-5	-1.67
Raburn	148	5	150	5	0	0	-5	-1.67
Guillen	630	19	600	18	6	17	-1	-0.33
Rodriguez	515	13	450	11	4	11	0	0.00
Santiago	74	2	150	4	3	8	+4	+1.33
Inge	577	13	250	6	4	11	+5	+1.67
Thames	284	7	200	5	4	11	+6	+2.00
Others	----	----	200	4	3	8	+4	+1.33
Totals	----	----	6200	213	52	144	-69	-23

Table 2: Win Shares for Tigers pitchers - 2007 vs 2008

	2007				2008		2008 - 2007
Player	IP	WS	EIP	EWS	WS	PWS	WS diff	W diff
Verlander	202	16	215	17	2	5	-12	-4.00
Willis	205	7	215	7	0	0	-7	-2.33
Zumaya	34	3	60	6	0	0	-6	-2.00
Robertson	178	8	185	8	1	3	-5	-1.67
Byrdak	45	4	50	4	0	0	-4	-1.33
Rodney	51	3	60	4	0	0	-4	-1.33
Seay	46	6	50	6	1	3	-3	-1.00
Miner	54	5	60	6	1	3	-3	-1.00
Jones	61	6	60	6	1	3	-3	-1.00
Grilli	80	4	60	3	1	3	0	0.00
Rogers	63	3	125	6	2	6	0	0.00
Bonderman	174	7	200	8	4	11	+3	+1.00
Galarraga	17	1	25	1	4	11	+10	+3.33
Lopez	9	0	25	0	4	11	+11	+3.67
Others	----	----	60	2	2	6	+4	+1.33
Totals	----	----	1450	84	23	65	-19	-6.33

Looking at the totals row in each table, we can see how many team win shares the Tigers would accumulate in 2007 if they performed the same way in 2008 as 2007. It comes out to 297 expected win shares in 2008 (213 for the batters and 84 for the pitchers). That is 99 expected wins assuming no injuries or player regression. So far this year, they have accumulated 75 win shares (52 and 23). Extrapolating that over 162 games, it comes to 209 win shares (144 for hitters and 65 for pitchers). That is equivalent to 70 wins.

So, if they keep up the same pace, the Tigers will lose 29 more games this year than expected based on their performance in 2007. Some of it is injuries to Curtis Granderson and Gary Sheffield and a few others but they haven't been hit that hard by injuries this year. So which players are underperforming the most?

Table 1 illustrates that six position players are underperforming by three or more wins over a full season.

Curtis Granderson (5.67 wins) - We can't blame Granderson for his hand injury but even if we lower his expected plate appearances to reflect time missed for the injury, it still comes to 4+ wins of underperformance.

Jacque Jones (5 wins) - Some people were not expecting much from him but he should have been expected to be a decent platoon player. Instead he had zero win shares at the time of his release.

Miguel Cabrera (-4.67) - He is tied for second on the team in win shares but he has simply underperformed. There is no excuse for him other than he is trying to adjust to a new league.

Magglio Ordonez (-4.00) - I'll excuse Ordonez for not repeating his career year of 2007. If I had used a three year average as the comparison rather than just last year, he would be performing just as expected. So, let's not blame Magglio.

Gary Sheffield (-3.33) - Sheffield has been hurt but he was hurt last year too so I wasn't expecting a full season of plate appearances from him. He has produced very little while playing though.

Edgar Renteria (-3.00) - Renteria had one of his best seasons last year but even if we take a three year average, he is still underperforming by more than 2 games.

On the pitching side, there are three players underperforming by 2 or more games:

Justin Verlander (-4.00) - He is apparently healthy and simply underperforming.

Dontrelle Willis (-2.33) - has been injured most of the season.

Joel Zumaya (-2.00) - has been injured all season.

My conclusion is that most of the team underperformance compared to 2007 is due to three things:

(1) the underperformance of the following players: Cabrera, Verlander, Granderson, J.Jones, Renteria and Sheffield.

(2) injuries to Zumaya, Granderson, Willis and Sheffield.

(3) Magglio Ordonez should not have been expected to repeat his amazing 2007 season.

So, for those who want to point the finger, there is plenty of blame to go around. For those who like to make excuses, there is some reason for that too. Regardless of how you look at it, it's been a very disappointing season for the Tigers.