In all the recent talk about to what extent Ron Roenicke is to blame for the Brewers' wretched first third of the season, I think there's a consensus that he's responsible for four areas of interest: bunting, bullpen management, line-up construction, and aggressive baserunning. The last of these has been sticking in my mind, since I think we take it as given that Roenicke's overaggressive on the basepaths, and this leads to extra TOOTBLANs and innings being lost. With the help of Baseball Reference, I decided to take a look at the progression of the Brewers over the last four years -- the Roenicke era plus Ken Macha's last year -- when it comes to outs given up and extra bases taken by runners. (Note: All counting stats for 2013 are projected from 48 games to 162.)
Since obviously the make-up of the roster will influence running tendencies, some background first. The top five players by SB for each of these years, with net SB - CS in parens:
2013 (projected) - Segura (+41), Gomez (+24), Aoki (0), Weeks (+7), Lucroy (+3)
2012 - Gomez (+31), Braun (+23), Aoki (+22), Weeks (+13), Morgan (+7)
2011 - Braun (+27), Gomez (+14), Morgan (+9), Weeks (+7), Hart (+1)
2010 - Gomez (+15), Braun (+11), Weeks (+7), Escobar (+6), Hart (+1)
Some fun and not-so-fun facts here. Braun is -3 so far for 2013; Aoki's net 0 includes 2 TOOTBLANs at home plate that were officially CSs. Ramirez stole 9 bases in 2012, and Segura had 7 in his limited time. In 2010, Lorenzo Cain stole 7 in 8 attempts, and Randy Wolf had a stolen base. Prince Fielder was 2 for 3 stealing in his last two years with the Brewers.
As we'll see below, 2012 looks like an aberration, even though the top four base-stealers are still on the roster and have been joined by a new leader. This is reflected in the tremendous success rate that the team had as a whole, which is well above their 2013 pace. What you'll see in this table is two things. For both the Brewers and National League overall, the stolen base attempt rate (SBA%), the rate of runners having the opportunity to steal who attempted to steal; the stolen base success rate (SB%), the rate at which those attempts were successful; and the net number of bases gained (SB-CS), successful minus unsuccessful attempts.
Then, I calculate the success rate for "extra" attempts -- that is, if we assume that the first X% of an above-average running team's attempts correspond to the league average, this is the success rate that would occur in the remaining Y% of attempts. Additionally, I calculate the net bases gained among those "extra" attempts. For a below-average running team, I do this in reverse, finding the rate that would get the team to the league average, plus the associated net bases. This is an assumption that's not necessarily or even likely going to be true, as evidenced by 2012, but it gives us a way to think about what running a lot really gets you.
The Brewers have had pretty close to league-average steal opportunities over the last four years (a bit below this year, a bit above in 2010), so these rates are basically comparable between the team and the league. The first thing that jumps out is that RRR didn't ramp the running up too much when he arrived. Ken Macha's last team had above-average success, but below-average usage. This was basically a wash, as they wound up 9 net bases shy of where they would've been as a league-average running team. RRR made them an average usage team (which is why there's no team-league difference to account for in SBX%), and they maintained above average success. Both of these two years, their net was essentially the same as league average.
Then in 2012, they didn't have to worry about not running in front of Prince Fielder, Gomez became an everyday player, Aoki arrived, etc. Attempts went way up, and success jumped noticeably as well. Those extra attempts turned into a big boost over the league average. But now success is way down and attempts are still up. That said, the net is still well above average, and those extra attempts more than account for the difference.
Stealing bases is only one part of the aggressive running philosophy, of course. The other balances TOOTBLANs and stretching for an extra base. I've long been of the belief that TOOTBLANs are highly salient events, and are susceptible to confirmation bias in light of RRR's eponymous reputation. Taking an extra base is less sensational, especially if it's not home. So in this table, we've got the Brewers and the entire league, with the good and bad of aggressive baserunning. First -- pick-offs (not including those that are officially caught stealing) and outs on the bases. Then, the percentage of all runners who are made out in those ways, i.e., the TOOTBLAN rate. Next, extra bases taken by runners, and that number as a percentage of all runners. Notably, this doesn't include stretching a hit for an additional base. Finally, extra bases taken minus TOOTBLANs.
Here, the Brewers have been worse than the league average every year of RRR's tenure, but his first year was very similar to Macha's last. Things started to skid in 2012, even as both rates went down. They're down again this year, and the team looks to be 40 bases behind the league average by the end of the season. This could be RRR dialing down the aggression, or it could be the roster. Something is clearly off with Braun in 2013, and having Yuni and Alex Gonzalez playing a lot certainly won't make running a priority. Team success probably plays role, too. RRR's first team had the luxury of using the running game to put the hammer down in pursuit of insurance runs. This year's team mostly can't afford that, and last year's couldn't for most of the season either.