Keep up with the latest news, notes and developments with Fungoes, a daily journal for all things baseball that will last all season long.
FanGraphs: Better than a Box Score
The Mets' home opener against the Phillies was a nail-biter up until the Mets' seven-run explosion in the bottom of the eighth. If you were to take a look at a regular box score, you might dismiss the game as a blowout, but a single glance at a Win Probability graph and it couldn't be clearer that this was a very exciting game:
Through the use of historical play-by-play data and some additional math, Win Probability tells us a team's chances of winning at any point in the game. The main chart tracks the Win Probability as the game progresses, play-by-play. The lower chart tracks something called Leverage Index, which is the potential importance of each play. The higher the Leverage Index is, the more important the play.
So let's take a look at some of the more exciting moments of the game from a Win Probability perspective:
From that point on, the Mets steamrolled their way to victory, ending the eighth with a six-run lead. They had a 99.7 percent chance to win at that point and the game was effectively over.
While I'm sure you found my play-by-play account utterly riveting, the graph does an excellent job of showing the entire game flow, not just the score. The score alone would not have told you the Phillies blew a great opportunity in the fourth, nor would it have told you Geoff Geary's wild pitch more or less sealed the Mets' victory.
But that's not all Win Probability is good for. You can calculate which players were the most valuable or least valuable to their team over the course of the game. This is done by determining the difference in the Win Probability at the start of the play and the end of the play, and then attributing it to the batter and pitcher. This is called Win Probability Added (WPA). (Click here for the WPA-enhanced box score.)
Using WPA we know that Geary pretty much blew the game for the Phillies by decreasing their chances of winning by 50 percent while Howard did all he could to get the Phillies to win, increasing their chances by 32 percent. No pitcher on the Mets was particularly effective, but Carlos Delgado and Jose Reyes were the real heroes, increasing the Mets chances of winning by 32 percent and 27 percent, respectively.
To see more Win Probability or learn more about it, here are a few places to get you started:
David Appelman is the creator of FanGraphs.com.
AL East blog (Monday)
NL West blog (Monday)
AL Central blog (Tuesday)
NL Central blog (Wednesday)
AL West blog (Thursday)
NL East blog (Thursday)
Wild Card (Friday)