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Key Stats to Watch (Part 1) - Starting Rotation

by Tim Muma
4/10/2012 (6:55pm)

This will be the first part in a series that will give you some non-standard statistics to keep an eye on to gauge the effectiveness and the potential success of each player on the 2012 Milwaukee Brewers' 25-man roster.

First we'll take a look at the five starting pitchers, because their results will most greatly affect a repeat division title.

Yovani Gallardo - Ground Ball to Fly Ball Ratio (GB/FB)

(GB/FB is telling because fewer fly balls make home runs and extra base hits less likely. Pitchers desire a high ratio in this respect, with league average at 8.0)

  • Gallardo has had three seasons with more than 20 starts, and his success has coincided with his GB/FB.

  • Last season was Gallardo's best campaign in terms of overall production and his highest GB/FB ratio at 0.88. In 2009, his 2nd-best season, Gallardo had a GB/FB of 0.83 - and in 2010 it sat below league average at 0.76.

  • Despite giving up 27 HR in 2011 (8th-most in baseball), Gallardo's high ground ball rate helped him avoid disaster. Had his GB/FB been lower, he most likely would have seen his ERA move near 4.00 because of the rate he was giving up long balls.

  • His opening day illustrated the issue (small sample)...his GB/FB was 0.40 and he gave up 4 dingers and 6 runs in the loss.

Zack Greinke - Batting Average of Balls in Play (BAbip)

(BAbip gives a "batting average" for any balls that are hit into the field of play, thus eliminating walks, strikeouts and HBP. This can help determine how a pitcher's defense - or plain luck - can affect his results)

  • Greinke had a solid year in 2011, but it was not among his best 3 seasons - though most pitchers would take his numbers, especially at Miller Park.

  • His BAbip last season was the second-worst of his career (.323), 12 points higher than his average.

  • The Brewers defense was the main culprit in turning outs into hits in 2011, probably costing Greinke a couple of wins and 0.25 off his ERA.

  • Should he pitch as well as he did last season and see his BAbip drop to his career norm of .311 due to an improved defense, Greinke will be poised to post Cy Young numbers.

Randy Wolf - Walks per Nine Innings (BB/9)

(BB/9 measures how many walks a pitcher gives up for every nine innings he throws, a large factor in runs allowed)

  • Of Wolf's top 6 seasons as a pitcher with 20+ starts, all but one of those years had a BB/9 of 2.8 or lower.

  • In each of his other seasons, his BB/9 sits at 3.4 or higher - a substantial amount of base runners over the course of 180-200 innings.

  • Because Wolf is not overpowering and relies on command, limiting walks is essential as he will give up a high number of hits. With runners on base due to walks, more of them will score and create spikes in his ERA.

  • His first start was an example...Though he gave up 9 hits in 5 innings, he only allowed 3 runs because only 1 batter reached via a walk.

Shaun Marcum - Percentage of Hits That Are Extra Base Hits (X/H%)

(X/H% gauges a pitcher's ability to limit extra base hits over the course of a season. A pitcher who gives up mostly singles - less harmful than extra bases - will have a lower percentage with this stat)

  • From 2006-2011 has lowered his X/H% each season, dropping it from 41% in 2006 down to 33% last season.

  • Again, a low percentage in X/H% means a pitcher can allow a higher number of hits without watching his ERA balloon upward, as it takes 3 singles to score a run versus a single and 2 doubles plating 2 runs.

  • This stat (like most) is not meant to be seen in small samples, but over the course of many starts.

Chris Narveson - Strikeout Percentage and Walk Percentage (SO% and BB%)

(These stats measure the percentage of total plate appearances that end in a strikeout or end in a walk respectively)

  • Over the past three seasons, Narveson's numbers have trended negatively in both categories.

  • His SO% has gone down each year from 22.4% to 18% (still above league average, however).

  • Narveson's BB% has increased each season, rising from 7.8% to 9.2%, which is nearly a full percentage point above league average.

  • While his stats haven't been enormously affected by these two trends, these are definitely something to watch moving forward...particularly as he begins his age 30 season.

Just trying to give you some other things to look at when trying to figure out if someone's ERA is going to last (good or bad), if the carousel of base runners will continue or how good the defense might be. It's really not feasible to only rely on the standard statistics anymore


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Brewers Mix blog featured writers Tim Muma, John Linn
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