The Yankees with no Moby Tom M. Tango
May 05, 2012
The following article first appeared in the 2011 Hardball Times Annual.
Mariano Rivera had pitched in 917 games through 2009. In his first two years, he was still establishing himself and his eventual role. Once John Wetteland left, Rivera was the undisputed ace of the Yankees bullpen. Let's break down his 837 games as ace reliever, and see how the rest of the Yankees bullpen has fared in comparison during that time.
Ninth inning, ahead or behind
As we have shown in the past in The Book, a three-run lead heading into the ninth inning is a very safe lead. While an ace reliever will protect that lead 98 percent of the time, an average reliever will protect that lead 96 percent of the time. Basically, it’s tough to add value when everyone else is finding success in the same situation. So let’s see what happened with Rivera and his backups.
Rivera was brought into a game to protect a three-run lead 124 times (116 times with no outs, four times with one out, and another four times with two outs). The Yankees won 122 of those games. The rest of the Yankees bullpen, when given a three-run lead, was even better. They protected that lead every single time. When a saberist says that just about anyone can save a three-run lead, well, this is what we are talking about.
Let’s start keeping a running total:
Subtotal (three-run lead): Rivera, minus two wins.
In the ninth inning with a two-run lead, Rivera entered the game 141 times, and the Yankees won 139 of those games. Seems pretty impressive. The rest of the Yankees bullpen, however, never lost a game with a two-run lead! Subtotal (two-run lead): Rivera, minus two wins.
How about a one-run lead? The Yankees won 122 of the 138 times Rivera entered such a game. If we focus on those in which there were no men on base and no outs when Rivera entered, he went 120 for 135. The rest of the Yankees bullpen faced only 19 one-run situations in the past 13 seasons, and the Yanks came away with the win 15 times. Prorating up to 135, that comes out to 108 wins. Big edge to Mariano. Subtotal (one-run lead): Rivera, plus 12 wins.
With a four, or more, run lead in the ninth inning, Rivera was 130 for 131, a match for the rest of the bullpen. Subtotal (four-plus runs lead): Rivera, no wins.
Rivera also came into a game with the Yankees trailing in the ninth 34 times, and the team eventually won five of those games, which is a bit better than the four that the rest of the bullpen delivered. Subtotal (behind): Rivera, plus one win.
Ninth inning, tied game
Now let's look at tied ballgames. The Yankees won 43 of the 76 tied games that Rivera entered. Of those, 61 games were in the top of the nnth at home, with the Yankees still having a chance to bat. They won 37 of those games. The rest of the Yankees bullpen won 16 of 30 similar games, which prorates to 32 wins, making Rivera plus five wins in this category.
Rivera came in to start the bottom of the ninth in tied games only eight times and the team won five of those. The rest of the Yankees bullpen won 35 percent of its games, which prorates to three wins, making Rivera plus two wins.
Rivera came in another seven times in tied games in the ninth inning under various other base/out configurations. The team won only one game. Pro-rating the rest of the Yankees bullpen onto Rivera's opportunities, and they won four times, making Rivera minus three wins. Subtotal (tied): Rivera, plus four wins.
Overall, in the ninth inning, Rivera was 13 wins better than the rest of the Yankees bullpen.
What about the other innings? Repeating the exercise, and controlling for the various base/out/score configurations, here's how Rivera compares to his bullpen in total:
- Extra Innings: Rivera minus one win
- Ninth Inning: Rivera plus 13 wins
- Eighth Inning: Rivera plus seven wins
- Seventh Inning: Rivera minus one win
- Total: Rivera plus 18 wins.
|Inning||Score||Games||Wins||Win %||Wins vs other Yanks relievers|
|7th||Up By 1|
|7th||Up By 2|
|7th||Up By 3|
|7th||Up By 4+||2||2||1|
|8th||Up By 1||56||50||0.893||6|
|8th||Up By 2||39||35||0.897|
|8th||Up By 3||29||28||0.966|
|8th||Up By 4+||18||18||1||1|
|9th||Up By 1||138||122||0.884||12|
|9th||Up By 2||141||139||0.986||-2|
|9th||Up By 3||124||122||0.984||-2|
|9th||Up By 4+||131||130||0.992|
|10th+||Up By 1||9||8||0.889|
|10th+||Up By 2||1||1||1|
|10th+||Up By 3||4||4||1|
|10th+||Up By 4+|
Mariano Rivera has been 18 wins better than the rest of his bullpen over his career. That’s fewer than two wins per year. I know it's a shockingly low figure, but that’s what the method shows.
A measure such as Win Probability Added (WPA) gives Rivera an impact of plus 44 wins above the average pitcher from 1997-2009. However, WPA compares a player against the league average, and you can be sure that the Yankees bullpen would have been better than a typical major league bullpen, even without Rivera.
Also, the Yankees certainly would use a better pitcher in a close game than your typical major league reliever. This raises the bar against which Rivera is compared, turning the +44 wins that WPA gives him to +18 wins in the more detailed method offered here.
By the way, we are ignoring the fact that Rivera has been possibly the best pitcher ever in postseason history. That certainly counts for a great deal.
If the Yankees can keep finding arms, they should be able to weather Rivera’s loss at an impact of under two wins a season. Two wins is plenty, something that teams pay an extra $10 million for. And, that's pretty much what's going to happen as the Yankees might go from a $15 million dollar ace to the typical $5 million next-best reliever.
Just as it was not the end of the world when the Twins lost Joe Nathan—a team that that is currently (as I write this in late August, 2010) sixth in the majors in WPA for relievers, about 1.2 wins less than the Yankees bullpen—so too might the Yankees be able to absorb most of the loss of Mariano Rivera.
Tom has co-authored a baseball strategies book called The Book - Playing The Percentages In Baseball, which is available at Inside The Book. Readers are encouraged to post comments on the author's blog, or to send him an email.