From Saltillo With Heat – Nats Sign Martin

Posted by Harry Pavlidis on Thursday, February 25, 2010 at 8:39 pm

The Washington Nationals, perrenial seekers of bullpen arms, made an interesting move this week by plucking Rafael Martin out of the AAA Mexican League.

The Nats purchased Martin’s contract from the Saltillo club, according to reports, and he may have actually signed the deal a couple weeks ago. Federal Baseball has some links on the news and how it came out. Martin has been reported to possess a 94-95 mph fastball, which is naturally appealing to a big league club.

But what else do we know about Martin? From his statistics, it looks like he figured it out last year. That’s based on a small sample size, as he’s almost exclusively been used in  relief. His presence in the 2010 Caribbean Series isn’t meaningful, as his whole team qualified by winning the Mexico’s winter league title. Still, he got in to two games of the six during the Series week.

So, what about that statistical improvement?

If there’s one feature of the Mexican League, it’s the pitchers tend not to strike out many hitters. The league also has a pretty high ground ball rate, relative to other minor leagues. To find more ground balls, you have to go down from AAA, past AA, right on by High A and into the Low A and Short Season A levels. And rookie ball. Whether it’s the hitters or the pitchers, you have to consider a pitcher’s performance relative to his league.

The Mexican League averages 13.3 strikeouts per 100 plate appearances. No other league is close. The Venezuelan Summer League (Rookie, 17.3) and Texas League (AA, 17.5) are the only others averaging less than 18 K/100.

Let’s start with the raw numbers on Martin, taken from baseball-reference.com.

ERA schmeeRA. The strikeouts and walks are suddenly inline and looking good. Well, that walk rate may be a little on the high side … let’s look at some more numbers, relative to the league.

As with things like OPS+, 100 is set to league average. 110 is 10% higher than average, 90 10% lower and so forth. The numbers below are taken directly from MLBAM’s Gameday and include batters faced (PA), strikeouts per 100 batters (K), walks plus hit batters per 100 (BH) and the four batted ball types per ball in play (including home runs).

Let’s pretend the sample sizes are meaningful. Martin’s K rate jumped, along with his pop-up rate. Both would be signs of nastiness, all else being equal. For pop-ups, though, his actual rates went from 9.5% to 9.7% to 11.2% — so not such a big deal in the grand scheme of things.

The drop in walk rate shows that he went from the bad side to the good side of a seemingly high-walk league. Along with his strikeout rate, as we saw in his baseball-reference line above, there was an apparently substantial change in performance.

His ground ball rate, even with the rebound, isn’t impressive for the league. If somehow his actual rate translates to the majors (47% in 2007 and 2009), then he’ll be in good shape (MLB average is 43%). The drop in line drive rate is also impressive, but there are always questions around what is tagged as a fly ball and what’s a line drive.

However you cut it, Martin pitched far better in 2009 than either of the previous two. The Nationals will probably keep him in AAA to start 2010, where we’ll get some idea of how he looks against International League competition.