Ron Gardenhire announced after Wednesday’s game that Brian
Duensing was guaranteed a spot in the starting rotation. This news was pretty
much anticipated given Duensing’s performance as a starter the previous two
seasons coupled with the other candidates’ injuries and ineffectiveness.
Without question, Duensing pitched admirably for the Twins
last season, acting as a vital cog in assisting the Twins to their second
consecutive division title. Still, based on his peripherals and his average-ish
stuff overall, there are some who believe that a repeat performance is unlikely.
On the other hand, Duensing now has proven in two samplings that he is capable
of handling the job, perhaps one of those rare breeds of pitchers who consistently
outperform their peripherals.
Since we can’t measure heart or analyze his mentality, let’s
take a look at some of the data from last year and see if it can tell us anything
about his future performance:
Brian Duensing’s Efficiency (2010)
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Category:
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Selected Outings
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MLB Average
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Grade
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% of PA’s that go to 3 ball counts:
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15%
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20%
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A+
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1st batter of inning out%:
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79%
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67%
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A+
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3 or less pitch PA’s:
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52%
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45%
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A
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4 or less pitch PA’s:
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71%
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65%
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A
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(via MyInsideEdge.com)
As you can see, Duensing thrived in this department comparative
to the rest of the league. These are the qualities that a manager loves – get the
first guy out and don’t lull your defense to sleep by throwing a ton of pitches
in an at-bat.
According to BaseballProspectus.com’s
run expectancy chart for 2010, the difference between letting the first
runner of an inning on base versus retiring him was 0.59 runs. By keeping the
first hitter from reaching, Duensing undoubtedly shaved plenty of would-be runs
off of his ledger.
This is unquestionably good. The problem occurs when you ask yourself if any of these skills are repeatable. Certainly, Duensing’s ability to pepper the strike zone and entice contact quickly in the count is a skill that can carry over, but then you have to wonder if more of those batted balls in play will start to go for hits – particularly doing the first at-bat of an inning thereby increasing an opponent’s ability to score runs.
Likewise, Duensing also exhibited some bulldog-like tenacity
when painted into a corner last season:
Brian Duensing’s Battle Tendency (2010)
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Category:
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Selected Outings
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MLB Average
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Grade
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% of runners who score:
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18%
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24%
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A
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% of 2-0, 2-1 & 3-ball counts ending in outs:
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79%
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67%
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A-
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(via MyInsideEdge.com)
With runners on base, Duensing was able to keep runners from
scoring and when he fell behind hitters, he rarely let them off the hook and
retired 79% of them.
Given these marks, mixed in with his traditional results of
a low ERA and an enviable win-loss record, you can see why Ron Gardenhire
tapped him as his third starter. However, the concern over those categories is
that they tend not to be repeatable. For
example, Duensing’s 18% runners who score mark is also analyzed as
left-on-base% at Fangraphs - measuring a pitcher’s ability to strand runner.
This quirky
video outlines the influences of the strand rate and that someone like
Duensing, who had a vaunted 82% left-on-base%, will be vulnerable to
regression.
Furthermore, while wowing everyone with his efficiency and
his battle tendencies, Duensing did not impress so much in regards to opponents’
contact:
Brian Duensing’s Overall Effectiveness
(2010)
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Category:
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Selected Outings
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MLB Average
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Grade
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Well-hit average (of
AB’s):
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.249
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.203
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C+
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Well-hit average (of strikes):
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.103
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.075
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C
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(via MyInsideEdge.com)
In general, Duesning’s offerings, when put into play, were
fairly well struck. The well-hit averages were not absurdly high, mind you, but
enough to lend credence to the notion that Duensing’s miniscule batting average
on balls in play in 2010 is likely to change routes next season. Along those
same lines, as I
discussed last month, right-handers have slapped him around a bit more and
with an increased exposure to opposite-handed hitters, Duensing will likely see
some of those numbers inflate to some extent.
Additionally, as impressive as his 7-2 record was as a
starter last year, some of that has to be attributed to a substantial amount of
offense provided by his lineup. His 5.67 runs per start – the 12th-highest
in the AL with a minimum of 70 innings pitched - gave him an ample cushion in
which to pitch in, much more so than the league-average of 4.45 runs per game. Given
that his runs per start will decrease toward the league average and his penchant
for allowing runs will increase some, there will be the likelihood of more
marks in the loss column in 2011.
Based on the level Duensing has produced at, it imposes an
unreasonable expectations for his future production when considering some
factors like his miniscule batting average on balls in play and astronomically
high left-on-base rate. Of course, none of this means that he shouldn’t be in the rotation –after all,
he has not allowed many home runs and has kept opponents off-balanced enough to
get them to drive the ball into the ground - it’s just a friendly reminder for
people to keep their vaunted expectations in check. If the defense behind him
can convert, he’s likely headed for an ERA closer 4.00 which, all things
considered, is not a terrible rate.
