(ed. note - "For Saturday Night's Game Report Click Here...")

I've recently realized that my attempts at stats posts are actually poor imitations of stuff Chris Needham did on his now-defunct Capitol Punishment blog.  So I've decided to embrace it and outright steal some of his concepts.

One thing I always enjoyed was when he'd take a look a win-percentage added (WPA) charts to see what the biggest plays had been in recent games.  WPA is fun stat based on a historical analysis of baseball games (check fangraphs for examples going back to 1974!).  A ballgame is in a clearly-defined state after every play: there are so many outs, men on certain bases, and the home team is ahead or behind by so many runs.  What WPA charts do is look at every game after each play, and compare it to a database of thousands of ballgames and say, "in this situation (bottom of the 3rd, 1 out, runners on 1st and 3rd, home team behind by one run), what percentage of times did the team win?"  The chance of winning changes after every play (score a run? it goes up! Make an out? It goes down!), and the amount (the WPA) it changes gives us a way to rank the big plays. (WP starts at 0.5 and goes up to 1.0 when you win, or down to 0.0 when you lose.)

Here are the 10 biggest plays from the last week (after the jump)--see how many you recognize!  And see if you can guess what #1 will be before starting the list.  Note that I'm including plays where WPA was lost (through an error or mistake pitch).  The big plays aren't always good ones

10). Austin Kearns, vs. O's (5/17/08): -0.176 for striking out with the bases loaded, down by one.

9). Jesus Flores, vs Mets (5/14/08): +0.187 when he singled in Elijah Dukes for the go-ahead run in an eventual 5-3 Nats win.

8). Ryan Zimmerman, vs. Mets (5/13/08): +0.192 for a two-run homer in the 3rd in a 6-3 loss.

7). Ronnie Belliard, vs Marlins (5/11/08): +0.198 for a tie-breaking, two-run homer in an eventual 5-4 Nats loss.

6). Aaron Boone/Cristian Guzman, vs Mets (5/15/08): +0.204 when Reyes tried to go first-to-third on Castillo's Sac bunt in the 8th.  Boone fired the ball to a sprinting Guzman, who got Reyes with a behind-the-back tag.

5). Jesus Flores, vs Mets (5/12/08): +0.246 for a tie-breaking, two-run, two-out double that put the Nats ahead for good in a 10-4 pummeling of NY.

4). Austin Kearns, vs Mets (5/13/08): -0.270 for misplaying Ryan Church's liner into a two-run double in a 6-3 Nats loss.

3). Luis Ayala, vs Marlins (5/11/08): -0.292 for giving up the game-losing homer to Dan Uggla in a 5-4 Nats loss.

2). Luis Ayala, vs Marlins (5/11/08): -0.294 for giving up a game-tying, two-run homer to Jeremy Hermida two batters earlier in the heartbreaking Mothers' Day loss.

And the number one play of last week (drum roll, please):

1). Aaron Boone, vs Mets (5/15/08): +0.408 when he caught Delgado's lined shot and threw to Zimmy to double Beltran off third, getting the last two outs in the triumphant 1-0 Nats win.