Wednesday, January 21, 2009
Why one closer over another?
Posted by Derek Carty at 1:08am |
| Joel Hanrahan might not be a household name right now, but he could be just as valuable as a guy like Mariano Rivera and come at a fraction of the cost. (Icon/SMI) |
Around this time last year, I showed that saves are unpredictable and explained why I don't like paying much for them on Draft Day. Does that mean, however, that we should treat all closers as precisely equal commodities and flip a coin to decide which one to take in any given situation? Of course not. If Mariano Rivera is sitting next to Fernando Rodney in Round 20, is it a toss-up? No, sir. I'm taking Rivera, and so are you. But why?
The answer deals largely with probability. While both Rivera and Rodney are expected to start the year closing games (assuming the Tigers don't sign someone like Brandon Lyon), what's the probability that each will end the year closing games? I'm sure most would agree that Rivera is a much surer bet than Rodney to still be closing games in September. But how do we quantify the difference?
I'll be the first to admit that the process I'm about to outline is a bit subjective, but that's the only way we can do this. This will change based on your own judgments of situations, but hopefully the process I lay out will prove useful.
When looking at how long a closer will last, there are two primary probabilities we much come up with: the probability of injury and the probability that poor performance or managerial whim will lead to removal. Also, if you're drafting early and the team's closer hasn't been announced yet, the probability of winning the job is important too.
To elaborate further, the injury probability isn't the probability that a player will get injured, because that begs the question "how long?" Instead, the percentage of time we expect the player to miss due to injury. As a guideline, one month is roughly 17 percent of the season.
The save system
Now let's take a look at how you might go about putting this all together. For our purposes today, keep in mind that these figures aren't based on any real measurements. They are quick estimates simply to show you how this should be done.
To keep things simple, I'll ignore the impact of team quality on save opportunities and the impact of closer skill on save conversions, since the effects aren't that large. If we were to do this in a more scientific manner, both would need to be considered, although there would be a heavy regression to the mean component since there is so much random variation in these things (check out the article I linked in the first sentence to see more precise figures).
In this vein, I assigned every closer 42 save opportunities (which I got by taking the average number of opportunities for all pitchers who closed the entire year in either 2007 or 2008) and a conversion percentage of 88 percent (the aggregate rate for this same set of pitchers).
+-----+-----------------+-----+---------+--------+---------+-----+----+ | ADP | CLOSER | SVO | GET JOB | INJURY | REMOVAL | SV% | SV | +-----+-----------------+-----+---------+--------+---------+-----+----+ | 9 | Joakim Soria | 42 | 100% | 11% | 3% | 88% | 32 | | 7 | Mariano Rivera | 42 | 100% | 15% | 6% | 88% | 30 | | 18 | Joel Hanrahan | 42 | 97% | 12% | 10% | 88% | 28 | | 23 | Fernando Rodney | 42 | 65% | 22% | 60% | 88% | 7 | +-----+-----------------+-----+---------+--------+---------+-----+----+Note: I didn't include it in the table above, but for some closers, you could add another column with the percentage chance that the pitcher is traded to a team who will only use him as a setup man or that the team will trade for a closer to supplant him. In 2009, this could apply to a guy like Huston Street or Jonathan Broxton.
Again, while these are based on some quick, subjective judgments on my part, you can see that — strictly in terms of saves — it is completely unnecessary to take a closer in the early portion of a mixed league draft. Under this method, early round options like Joakim Soria and Rivera would be just as good of bets as Joel Hanrahan, who could come a full ten rounds later.
As long as you're making reasonable assessments and you pick the right late-round closer options, you will be making the correct percentage play. Of course, if you pick the wrong option, you could wind up with Rodney's seven projected saves (ADP: Round 23).
But remember...
It's very important to keep in mind that this method will not parallel real world results, and using it will severely decrease the value of closers in comparison to the rest of the player pool. Even if we assign a closer who is 100% to win the job a 0 percent injury score and 0 percent removal score, he would still only project out to 37 saves. The save leader next year will have far more than 37 saves.
The problem is that whoever this is will get there through a lot of good luck, something we simply can't project. Therefore, when making your projections (or looking at someone else's), it would be imprudent to assign any closer more than 40 or so saves, and certainly no more than 45. If you're using a set of projections that have several closers above 40 or 42 saves, I would definitely consider looking elsewhere for save projections.
Further implications
While a closer projected to save 45 or 50 games (or 35 or 40 games with poor skills, ala Todd Jones)—as some systems will project—might have 60 or 70 percent of his value tied up in saves, a closer projected to save 30 games might only receive 40 percent or so of his value from saves.
This is notable because, when evaluating closers using this method, it makes it more important to identify the closers with good skills. Not only will good skills decrease a closer's "Removal percentage", those good skills will translate to a better ERA, WHIP, and strikeout total, which now make up a greater portion of the pitcher's value.
Unless you're playing in a league of full owners who pay attention to peripheral stats (as many of you do), you can gain a bit of an advantage here. Closers are often known for great "stuff" and blazing fastballs, but they certainly don't need these things to succeed. Trevor Hoffman is a change-up specialist who throws his fastball just 86 MPH, but he is still a good pitcher, far better than a guy like Matt Lindstrom who can touch 100 MPH. Still, they are both being drafted around the 18th and 19th round.
Closing thoughts
Hopefully this provides you with a new, better way of evaluating a closer's save potential. Again, it's absolutely subjective, but many of these things simply can't be objectified, and this doesn't have to be a precise exercise. You can gain value from it simply by separating the Hanrahan's from the Rodney's. It doesn't matter if your judgments put Hanrahan at 25 saves and Rodney at 15; that's still a large enough gap to differentiate them for drafting purposes.
Derek Carty, 23, has also been published by NBC's Rotoworld, Sports Illustrated, FOX Sports, and USA Today. This season, he'll be contributing to FanDuel and will be linking to all of his work at DerekCarty.com. In his three years competing in expert leagues, he has won 2 titles with 4 top three finishes, including a LABR NL title in 2009, making him the youngest person to ever win a major expert league title. Derek is a proud graduate of the MLB Scouting Bureau's Scout Development Program and is a firm believer in the importance of combining stats and scouting. He welcomes questions via e-mail, Facebook, or Twitter.
There is one more calculation that can be made in this regard: expected (team) save opportunities.
There are some teams that generate more save opportunities than others. Good teams generally generate more than bad teams - and teams that play low scoring games get in more close games than teams that score and/or give up a bunch of runs.
Even though I have not done the work to yield a save opportunity predictor formula, in principle it would not be difficult to fit one with past data to determine expected team save opportunities.
One would expect, for example, that the Angels closer would get more save opportunities than the Orioles’ closer, because the Angels are expected to be a better team and are also a team that tends to play lower scoring games.