Back in May of 2010, FanGraphs began providing Shutdowns (SD) and Meltdowns (MD) in the Win Probability section of each pitchers’ page:

… there’s been a lot of discussion on The Book Blog about creating a save style metric based on WPA. The end result of the discussion was to create two stats: Shutdowns and Meltdowns.

A Shutdown is when a reliever accumulates greater than or equal to 0.06 WPA in any individual game.

A Meltdown is when a reliever’s WPA is less than or equal to -0.06 in any individual game…

The number of Shutdowns are scaled to Saves + Holds, which is where the .06 thresholds originated.

Well, I missed that party, but was lucky enough to get a proper introduction today when I read Steve Slowinski’s piece – he posited how, though they’ve been around nearly a year, they still feel “new.” Later, Rob Neyer picked it up and flipped it to his readership, applauding its usefulness while acknowledging the unlikelihood it’ll replace the save.

For those that don’t know, WPA stands for Win Probability Added. It’s more of a descriptive stat rather than one regarded as predictive, but it helps us to understand which players contributed most (or least) to a a single win, and over a full season. Read this primer at FanGraphs to get more familiar.

Anyway, a lot of Giants fans, me included, spent a lot of time trying to figure out who was Brian Wilson’s best replacement while he recovered from an oblique strain. Luckily, Wilson is back today and that’s no longer really an issue – at least presently, knock on wood. But still, a lot of crazy ideas were thrown around. For example, that Jeremy Affeldt was somehow a worthy candidate.

Now that Wilson’s back, it might still be useful to ponder which pitchers should be receiving the bulk of the high-leverage innings, seeing as how a game can easily be lost in the seventh and eighth inning just as easily as the ninth. We know that; that’s one of the real problems with how closers – typically a teams best reliever – are utilized. Ron Washington, for example, has a very long way to go in this regard.

I’m not going to spend a large chunk of time on this, other than to provide the numbers, assume you read the Shutdowns and Meltdowns concept above and through the link, and then provide the numbers for the prominent Giants’ relievers. Here goes:

Wilson has 130 career shutdowns and 38 career meltdowns – that’s a ratio of 3.42, good but not excellent. In 2010, however, he was quite excellent at 38:7 (SD:MD) or a ratio of 5.43. Though he was anointed an elite closer this past season, clicking the link above will reveal that seven others handedly out-shutdowned him in 2010 (Hint: Carlos Marmol, King Strikeout himself, was number seven with a ratio of 6.17.) I don’t think he’d at all be pleased to know this. But he’s the guy the other relievers on the Giants would want to try to emulate. We know it’s a tall order.

Unsurprisingly (to me, at least), Sergio Romo is his best replacement with a career 43:15 meltdown to shutdown ratio (2.87). In 2010, he basically pitched about exactly as well as he had throughout his career – he had a 20:7 ratio (2.86).

Javier Lopez is next in line: career 86:47 (1.82) and 2010 had 15:9 (1.67).

Then comes Santiago Casilla: career 86:47 (1.82) and in 2010 he ratioed 19:5 (3.8). I recently noted his drop in velocity of about 3 mph this spring, as well as what was observed in his first outing on Opening Day. So it was not shocking, then, when the Giants placed him on the 15-day disabled list when activating Wilson on Wednesday. In fact, it was telegraphed like a haymaker in slow motion.

A lot of folks liked Affeldt for the job – he’s not a bright choice: career 130:70 (1.47) and in 2010 he ratioed 8:14 (0.57), which happened to be the second worst ratio of any relief pitcher in 2010. People were almost certainly motivated to nominate him because he’d been excellent in 2009 with a 29:7 ratio (4.12). Despite the dominant 2009, his career SD/MD ratio is not very good at all, which should give us some feeling that he’s simply not a candidate for high-leverage innings. Many people tend not to realize how volatile relief-pitcher performance is. Affeldt’s rise and fall from 2009 to 2010 is a prime example.

I’ve also recently heard such ridiculous statements as: “I just don’t trust Romo, he’s always giving up big hits.” Well, he may not be Wilson, but he’s more trustworthy than Affeldt, Lopez, etc. Things like giving up game-wining home runs to Manny Ramirez tend to stick out in fans’ minds, while the countless number of times he whiffed batter after batter with his patented Frisbee slider do not.  Biases develop throughout a long season and throughout several seasons while fans follow a team. The most significant moments often cloud the judgement of the observer. Be mindful of this – Aaron Rowand is not the worst player of all time, Barry Zito‘s not the worst starter. And no, Jack Morris is not a Hall of Famer despite his heroic, 10-inning shutout in game seven of the 1991 World Series; these biases go both ways.

So, as the season goes along I’ll probably be paying closer attention to this stat with the San Francisco’s bullpen. It really does a great job of telling us exactly which relievers are winning and losing ballgames.

Slowinkski definitely sold me on these two stats today. Click on the link above, and see if you aren’t a sucker too. His name kind of sounds like a used-car salesman, sure, but I promise it’s not all gimmicks.