FanPost

Fun with sabermetrics: evaluating the Rockies’ pitchers

Fellow Rowbots:

My name is Dan Hampton and I started a blog called Mountainball for a class project. I'm seeking feedback for a post I wrote on sabermetrics, particularly whether or not I'm using the metrics correctly. Feel free to check it out and comment below. Constructive criticism only, please, I'm still learning how to use read and use advanced metrics so I'm very aware I could be using them wrong.

Two weeks into the season, and by all accounts the Rockies are right where they should be. They’re 6-8 and only three games back from the Dodgers in the NL West. Tyler Chatwood came off the disabled list and Jhoulys Chacin will make his first rehab start Tuesday. Unfortunately Brett Anderson broke his thumb against the Giants and hit the disabled list, so the Rockies are still not going to be at full strength for another few weeks. But injuries are a part of the game, and every team gets them. The Rockies have much deeper issues that not many people are talking about – their pitching has been poor up to this point, and if their pitchers can’t figure out what’s wrong, the offense won’t be there to bail them out every game. Fielding Independent Pitching (FIP) is an advanced metric that measures what a player’s earned run average should have looked like over a given time period, assuming that performance on balls in play and timing were league average. The measurement attempts to assess how a pitcher has performed by eliminating variables out of his control (like defense). Similar to ERA, the lower the number, the better the pitcher is (supposedly). Expected Fielding Independent Pitching (xFIP) is just a regression of the FIP statistic. It replaces the number of homeruns given up by a pitcher with the number of homeruns they should have given up.ImageImageJuan Nicasio has been excellent so far leading all Rockies starters with a 2.97 FIP and a 2.93 xFIP, per Fangraphs. Given Nicasio’s history, he may not keep this up, but perhaps he’s starting to put it all together. New Rockie, Jordan Lyles, has put up decent FIP and xFIP numbers this season too, though his batting average on balls in play (BABIP) is likely a contributing factor there. Surprisingly, Lyle’s FIP is expected to improve a little bit even with the BABIP regression, though don’t be surprised to see it go the other way here. The most important takeaway here though, is that the Rockies’ projected fifth starter and a guy who’s supposed to be in AAA have thus far outperformed expectations. It’s actually the front end of the rotation that could end up a problem. Jorge de la Rosa. Though fans may never know the exact reason why he blew up on Wilin Rosario, de la Rosa hasn’t been any better with Pacheco. Despite an extraordinarily high 11.08 strikeout per nine innings rate, he’s walking nearly five batters in that time, giving up two homers per game and allowing 20% of fly balls to leave the yard, all while getting slightly lucky on balls put in play. One doesn’t have to look at the FIP and xFIP to see why that could be trouble. De la Rosa has been awful this year (per Fangraphs) leading to a FIP of 5.75 and an xFIP of 4.36. Although fans should expect to see him give up less homeruns, the walks are troubling, the K/9 is unsustainable, and his BABIP will regress closer to 3. This is not what the Rockies wanted out of the 33 year-old veteran, and if he can’t right the ship the Rockies better hope Chacin and Chatwood come back healthy and dealing. Otherwise it could be a long summer.

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