World Series MVP

(Quick note, I typed out this post in entirety before Blogger deleted the whole thing even though it is supposed to save, so this version is unfortunately a little shorter!)

Last Monday night, the San Fransisco Giants won their first World Series since 1954, when Willie Mays and the New York Giants won. Ironically, there has never been a World Series won by the Giants with a MVP, as the MVP award did not begin until 1955, the year after the Giants last one. Unlike previous Giants' teams, with superstars such as Mays, Willie McCovey, and Barry Bonds, this team was led by great pitching and a team that managed to get just enough timely hits to squeak into the postseason on the last day. In this post, I want to determine who should have been the MVP of this team, and whether or not the voters picked the right player (Edgar Renteria ended up winning the award).

We need to ask two questions before we decide who the MVP should have been. First, what exactly is the MVP? Obviously, it is the "most valuable player", but what exactly does that mean? Does it mean the best overall player? Obviously not, as only one player in World Series history has won the WS MVP while playing for the losing team (Bobby Richardson in 1960, when the Yankees outscored the Pirates 55-27 but still managed to lose in seven games). I believe that the MVP is the player that best gives his team the chance to win each game, and as a result the series. The question now becomes: how do you measure exactly how "valuable" a player is to his team? I am going to use the Win Probability Added statistic, which is the sum of the changes in the probability of a player's team winning. More simply, WPA "looks at" each play and determines the teams probability of winning before, and then after the play occurs, and the difference is debited and credited to the players involved. For example, if a team was winning in the ninth inning, there probability of winning would be fairly high, say 80%, but if a player on the opposing team then hit a home run to tie the game, and the probability of the first team winning fell to say 55%, then the player who hit the home run would have a +0.25 WPA for that play, and the pitcher who gave up the home run would have a WPA of -0.25 for the play. Each team starts at a 50% chance of winning, and one team ends with a 100% chance of winning, so WPA measures exactly how much each player individually contributed to winning the game. It is heavily dependent on the leverage of the situation, as obviously a go-ahead home run in the ninth inning gives the team a better chance to win than a go-ahead home run in the first inning.

To determine which player should be the MVP, I summed the WPA for each player during each game in the World Series to determine the overall World Series WPA. I have created two tables below, for the position players and the pitchers, which rank the players in terms of overall WPA for the World Series, and also which games they appeared in.

Players:

Player	World Series WPA	Games Played In
Edgar Renteria	0.403	1, 2, 3, 4, 5
Aubrey Huff	0.147	1, 2, 3, 4, 5
Andres Torres	0.139	1, 2, 3, 4, 5
Cody Ross	0.108	1, 2, 3, 4, 5
Freddy Sanchez	0.094	1, 2, 3, 4, 5
Mike Fontenot	0.000	2
Juan Uribe	-0.046	1, 2, 3, 4, 5
Travis Ishikawa	-0.057	1, 4
Aaron Rowand	-0.058	2, 5
Pablo Sandoval	-0.081	3
Nate Schierholtz	-0.091	1, 2, 4
Buster Posey	-0.154	1, 2, 3, 4, 5
Pat Burrell	-0.423	1, 2, 3, 5

Pitchers:

Pitcher	World Series WPA	Games Pitched In
Matt Cain	0.495	2
Tim Lincecum	0.477	1, 5
Madison Bumgarner	0.477	1
Brian Wilson	0.131	1, 4, 5
Santiago Casilla	0.059	1
Javier Lopez	0.047	1, 2
Sergio Romo	0.021	1
Jeremy Affeldt	0.021	1, 3
Guillermo Mota	0.020	2, 3
Ramon Ramirez	0.009	1, 3
Jonathan Sanchez	-0.162	3

As you can see above, three of the four most valuable players on the Giants in the World Series happened to be pitchers. Edgar Renteria was the only significant hitter with a .403 WPA, Matt Cain had a .495 WPA, and Tim Lincecum and Madison Bumgarner both had a .477 WPA. The question now becomes, do you give the MVP vote to a pitcher such as Matt Cain, who pitched brilliantly and had the highest overall WPA, but only appeared in one game, or do you give it to Edgar Renteria, who had a lower WPA but played in every game? The voters decided to give it to Renteria, and I tend to agree with them (another issue would have been which pitcher to give it to? All three pitchers were very close in WPA, and I tend to think they would have given it to Lincecum as he pitched in two games and had the performance most fresh in the voters' minds). In this case, the voters' "gut instincts" actually agreed with the statistics.

One final note of interest is the Giants overall 1.5 WPA (they won 4 games, each with a WPA of +0.5, and lost one game with a WPA of -0.5). Of that 1.5, approximately 1.6 WPA came from the pitchers, while the hitters actually had a negative impact on the probability of the Giants winning the World Series with a WPA of -0.1. So even though the Giants became the first team to score at least 20 runs in the first two World Series games, the pitching, just like all year, was the reason that they won the World Series. Ironic then that a hitter still managed to win the MVP.