Know Your Bullpens
by Trevor Whenham - 05/10/2007
This has probably happened to you more times than you can count - the starter for the team you have bet on has a decent outing, he hands it over to the bullpen with a comfortable lead, and you feel good. But then his relievers do their best impressions of a tee-ball tee and your money goes flying out of your pocket. I'm not sure that there is anything more frustrating than an implosion by a bullpen in an otherwise winnable game. Despite that, though, most baseball handicappers are guilty of spending too little time considering the bullpens when they make a pick in a game.
Starting pitchers are so fragile and carefully protected these days that it is notable when one goes past the seventh inning. In most cases, the bullpen will be called on to throw a third of the game. That's a significant reality. Of course, knowing that bullpens significantly affect outcomes of games is useless knowledge if you don't have a way to measure the impact and to profit from it.
The first thing you have to remember when looking at bullpens is that the ERA of the group often has little direct relationship to the effectiveness of the team as a betting proposition. Good teams often have good bullpens, but a struggling team can also have solid relievers and, in some cases, a team can be good despite who it hands the ball to in late innings. The results this year illustrate that well. The top two bullpens in baseball, the Mets and the Red Sox, also have the second and third best records in the league. Both teams have been profitable throughout the season. The next two on the list show the problems with relying on ERA as an indicator of profitability, however. San Diego has the third best bullpen ERA and the best opposing batting average, yet both their record and their betting performance have been disappointing. Their problem isn't who the starters hand the ball to, it's the starters themselves. Next up is St. Louis. The defending champs' bullpen has been performing as well as can be hoped, yet the wins just aren't coming, and they have been burning bettors' money all year.
It's also not as simple as assuming that a team is a bad bet just because they have a bad bullpen. The worst collection of relief arms out there, by a wide margin, belongs to Tampa Bay. They have a collective ERA of 5.52, and their .297 opposing batting average is high enough to make anyone look like an all-star when facing them. I very rarely bet on this team, and even still I've watched my money go down the toilet twice when it looked like a sure victory. Despite the crimes against humanity that this unit has committed, though, the Devil Rays have, by a small margin, been profitable over the year.
Though it's not particularly useful as a predictive tool, there is at least one bullpen stat that provides a good indicator of the betting success of a team - the difference between saves and blown saves. Milwaukee has had 14 more saves than blown saves, and Boston is just behind them with 12. Those have been the two most profitable teams all year. Atlanta and Arizona are next on the list, and they are both profitable. On the other end, two teams have had more blown saves than saves - Washington and the Yankees - and both teams have been betting disasters. Toronto and Florida both have just one more save than blown save, and both could have caused bankruptcy on the year. The gap between the stats isn't the cause of a team's success or failure, but it's a quick way to get a sense of the sustainability of their efforts.
In the absence of a quick statistical shortcut to evaluating bullpens, you actually have to do your homework to find the profitable opportunities. That's the kind of thing you have probably heard dozens of times before, and you probably know that you should, but it's easier to know what you should do in theory than to actually know exactly what you should be studying. The possibilities are endless, but here's a quick and dirty list of five places to start:
1. Long outings. If a game goes really long, or if a couple of games in a row go fairly long, then the bullpen has probably been forced to throw more than is ideal. Tired bullpens can lead to future losses.
2. Struggling starters. Take Jeff Weaver, for example. The way he is pitching now he's lucky to make it out of the second inning. That provides a lot of strain on the bullpen. That's not enough in and of itself to bet against Seattle, but if that's coupled with a tired bullpen then it could be a possibility.
3. Transactions. With the exception of the closer, the bullpen usually isn't filled with superstar pitchers. When a team is struggling or overcome with injuries, the talent level can really be challenging. Look for teams with a string of bullpen injuries, or one that has been recharging their troops with minor leagues or arms that other teams have discarded. That can indicate a bullpen in trouble.
4. Managerial tendencies. Not all managers use bullpens in the same way. Some like to use a pitcher for as long as they can, while others will alternate arms to create ideal match-ups between pitches and batters. Managers are usually pretty consistent when it comes to their habits, so the trick is to identify situations where they won't be able to do what they do best. If a manager is forced out of his comfort zone, profit can ensue.
5. Changes in form. It's not good enough to look at how a bullpen has fared over the course of the season. Even the worst bullpens can string together a couple of good games in a row, and the very best bullpens will occasionally throw a couple of games in a row away. By tracking how bullpens have been doing you can often spot, and profit from, these blips.