What caused K-Rod's fall

In 2004, Francisco Rodriguez was the best finisher in baseball, with the 95- to 97-mile-per-hour fastball and the nasty, impossible-to-hit hook. We don't have the statistics as far back as we'd like, but it's safe to say that his season was one of the best in major league history.

It feels like a long time ago.

That season, according to data found on Baseball-Reference.com, Rodriguez got to an 0-2 count on 75 hitters.

Do you know how many of those eventually reached base, whether on the 0-2 pitch or otherwise?

Three. For the entire season.

In 2009, his first year with the Mets, Rodriguez got to an 0-2 count on 53 hitters. Eight reached base.

That's not the K-Rod of 2004, but a .151 on-base percentage in those spots is still 52 points better than the league average for the 2009 season.

Francisco Rodriguez

After Getting Ahead 0-2

Flash-forward to 2010, specifically Wednesday's game when Rodriguez gave up ninth-inning hits to Tony Gwynn Jr. and David Eckstein on 0-2 counts, blowing the save in an eventual extra-inning defeat.

This is part of a pattern, one noted by some in the blogosphere. Let's attach some numbers to those thoughts.

In the San Diego game, Gwynn and Eckstein recorded the fifth and sixth hits against Rodriguez this season after he got ahead of a hitter 0-2 -- meaning on an 0-2 pitch, or any pitch after. In those situations, eight times in all, an opposing hitter has reached base.

When Rodriguez would previously get ahead 0-2, the hitter had about a 10%-to-15% chance of reaching base. Double that to better than 30% and you get the Rodriguez of 2010, one that has blown three saves in 13 chances.

The margin of error for a closer is very slim, so a sudden jump like that can be rather alarming. We'll leave the causes for the professionals to identify, but they would seem to start in two areas.

One is that his fastball velocity is down to an average of about 91 mph, and that's been noticed by many sources.

But the other potential issue is with his breaking balls.

We can isolate that over the last three seasons using our Inside Edge video review data. In doing so, we'll look at all two-strike situations. We'll also combine data for his curve and slider together since they're often tough to tell apart.

In both 2008 and 2009, Rodriguez yielded six hits with two-strike breaking pitches. But 2009 was a much different season than 2008.

When Rodriguez got his record-breaking 63 saves in his final season with the Angels, opponents hit .115 (6-for-52) against his two-strike curve/sliders.

In Rodriguez's first season with the Mets, they hit .286 (6-for-21). That's the same number of hits, and a LOT fewer outs.

That was offset by Rodriguez's success with his fastball and changeup, and the numbers show that those have been terrific weapons. Opponents are hitting under .100 this season in two-strike situations that end with those two pitches.

Those are his two best two-strike weapons. His other two are not working.

Rodriguez has already given up six two-strike hits with his curve/slider combo, the same number he yielded in each of the previous two years.

Francisco Rodriguez

2-Strike Breaking Ball Success

Combine that with a drop in his breaking ball "putaway rate" (strikeouts/pitches of that type thrown with two strikes) from 21% 2008 to 13% in 2010 and you can draw a rather simple, but stark conclusion: The two-strike breaking ball, which, when combined with the changeup, made Rodriguez a devastating pitcher to face, isn't what it used to be. That would seem to explain why he's not the finisher he once was.

For more on putaway rate, check out ESPN's TMI blog.

Mark Simon is a researcher for Baseball Tonight. Follow him on Twitter at @msimonespn or e-mail him at webgemscoreboard@gmail.com.