I’ve already covered some of the disappointments of the pitching staff so far this season. Everybody knew that the pitching staff and the starting rotation in particular would be a weak point for this Brewers team. On Tuesday night, however, the Brewers received yet another solid start out of David Bush, the #4 starter. Bush allowed no runs in seven innings of work, allowing only three hits and four walks while striking out two. The nine inning, one run performance put together by Bush, Chris Narveson (who allowed a home run in the 8th) and Manny Parra lowered the Brewers team ERA by a whopping .41 runs to 5.65.
Bush is currently the only member of the starting rotation with an ERA below 5.50. Bush has gone at least 5.2 innings in each start and has left each of them with the lead. In particular, Bush has done a great job of limiting walks allowed and has done a decent job of suppressing the home run – his 2.89 BB/9 is lowest on the starting staff and his 0.96 HR/9 is lower than any single season total he’s ever recorded.
However, Bush’s success almost certainly won’t continue if he can’t pick up the strikeout rates. Bush only has 10 strikeouts in 18.1 innings pitched this year, which comes in at a Jaime Navarro-esque (yes, I mean this guy) 4.89 K/9. That’s what has left him with an unimpressive 4.46 FIP, roughly in line with his career numbers.
What we’re seeing with Bush is what we see with a lot of low-ERA pitchers in small sample sizes – he’s had good luck on balls in play. His BABIP right now is sitting at a mere .220, about 80 points below the league average. Bush has allowed 55 balls in play so far and only allowed 12 hits, where we would expect either 16 or 17 out of a league average.
The question, then, is what to expect out of him going forward. First of all, I don’t expect Bush’s strikeout numbers to remain so low. He’s still drawing the same amount of swinging strikes as last season, and that’s a leading indicator of strikeout numbers. I’d expect that number to sit closer to the 5.50-6.50 K/9 range given Bush’s career numbers. Perhaps the most interesting thing to note is Bush’s much higher ground ball rate through 3 starts. Part of Rick Peterson’s goal as the new pitching coach is to emphasize ground balls with his pitching staff, and Bush certainly seems to be following that philosophy so far this season. That will be key for Bush, as he’s been killed by the home run ball the last two seasons mostly due to a fly ball rate above 40%. Even with a similar HR/FB rate in 2010 to the rest of his career, he’s allowing far fewer home runs per inning due to a much lower 38.5% fly ball rate.
A transformation into a ground ball pitcher for Bush would be incredible for this pitching staff. Bush is a very productive pitcher when he’s not allowing home runs, but his fly ball tendencies have led him to give up many a bomb over the course of his career. We saw this last season with the emergence of Joel Piniero as an extreme ground ball pitcher – I don’t think that Bush will improve to that level, but I do think it’s a good analog for what can happen when a pitcher drastically increases his ground ball rates. If he can continue with this ground ball success, he can be a huge asset to Milwaukee this year.