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I liked the Twins' decision to pluck Scott Diamond from the Braves' farm system in the Rule 5 draft, writing at the time that "he's had success at every level" and "may be able to find success in the big leagues without missing a ton of bats" because he "has done a tremendous job inducing ground balls and limiting homers" in the minors. That was December of 2010 and later that offseason I ranked Diamond as the 36th-best prospect in the Twins' farm system.

I hated the Twins' decision to trade Billy Bullock to the Braves for Diamond to circumvent the stipulation that Rule 5 picks must remain in the majors all season or be offered back to their old team. It seemed silly to give up Bullock, a hard-throwing reliever drafted in the second round and given a $533,000 bonus just a year earlier, when the Twins already had Diamond and could have retained him simply by keeping him on the roster as a long reliever at age 24.

Diamond ended up spending nearly the entire second half of last year in the majors anyway, meaning the Twins basically traded Bullock for the ability to keep him in the minors for an extra three months. And in those three months Diamond had a 5.56 ERA at Triple-A, so it wasn't surprising when the left-hander struggled in his first taste of the big leagues with a 5.08 ERA and ugly 19-to-17 strikeout-to-walk ratio in 39 innings while allowing opponents to hit .317.

Bullock had issues of his own following the trade with a 4.44 ERA and 34 walks in 51 innings at Double-A, but he still threw in the mid-90s and still racked up 11.7 strikeouts per nine innings while holding opponents to a .199 batting average. Bullock continued to look like a potential late-inning reliever, Diamond continued to look like a potential back-of-the-rotation starter, and the Twins' thought process behind the trade continued to make little sense to me.

Despite making seven starts for the Twins down the stretch last season Diamond was never in the mix for an Opening Day roster spot this season, getting sent back to Triple-A as part of the first round of spring training cuts. He fared well in Rochester with a 2.60 ERA in six starts, but also allowed opponents to hit .270 and managed an unimpressive 26 strikeouts in 35 innings as a 25-year-old spending his third consecutive season at Triple-A.

When injuries and ineffectiveness wrecked the Twins' rotation for a second straight year they again turned to Diamond, calling him up on May 5. In returning to the majors Diamond brought with him a 4.50 ERA in 39 total Triple-A starts, which along with his modest 6.3 strikeouts per nine innings there and the equally modest fastball velocity he showed in debuting last season seemingly provided little reason for optimism.

And so naturally six weeks later Diamond has a 1.61 ERA through seven starts.

You can call it fluky or lucky or unsustainable or maybe even none of the above, but obviously Diamond isn't going to maintain a sub-2.00 ERA for very long. However, in watching Diamond's seven starts this season compared to his seven starts last season it's just as obvious that he looks like a much different pitcher. Looks can be deceiving, of course, but a deeper inspection of his numbers also shows significant improvement along with some good fortune:

YEAR     PA     SO%    BB%    HR%     GB%     LD%     BIP     LOB
2011    181    10.5    9.3    1.7    46.2    21.0    .338    67.4
2012    183    15.3    2.2    2.2    61.7    20.8    .308    82.6

Diamond faced 181 batters last year and has faced 183 batters this year, so while small the sample size is equal. He's gone from as many walks (17) as strikeouts (19) to a 28-to-4 ratio, increasing his strikeouts by 46 percent and decreasing his walks by 76 percent. He's allowed the same number of line drives and actually given up more homers, but Diamond's ground-ball rate went from neutral at 46 percent to among the league leaders at 62 percent.

He's also seen his luck even out a bit, as his batting average on balls in play went from .338 to a more typical .308 and his percentage of runners stranded on base went from slightly worse than average at 67 percent to substantially better than average at 83 percent. In his second go-around as a major leaguer Diamond's pitching and luck have both improved dramatically, although what he's thrown and how he's thrown it haven't changed all that much:

YEAR     PA     FB%     MPH     CB%     MPH     CH%     MPH
2011    181    58.4    88.9    27.7    79.9    14.0    83.0
2012    183    63.2    89.6    27.8    81.2     8.9    83.9

Compared to last year Diamond has cut down on his changeup in order to throw eight percent more fastballs while utilizing his curveball the same amount. He's added around one mile per hour to each of his three pitches, but Diamond's average fastball still clocks in at just 89.6 mph to rank 131st out of the 168 pitchers with 30 or more innings this season. His repertoire has been pretty similar, with a few tweaks, and the per-pitch results are also similar within that:

YEAR     PA    STR%    ZON%    1PS%    SWG%    MIS%
2011    181    63.3    49.4    59.5    45.9    15.9
2012    183    65.6    51.8    61.1    44.3    13.0

Diamond has gotten slightly more strikes, thrown slightly more pitches in the strike zone, and jumped ahead of batters with first-pitch strikes slightly more often, but all three of those rates are within a couple percentage points of last season and he's actually induced slightly fewer swings and slightly fewer misses than in 2011. Add it all up and Diamond's results are vastly improved, but his raw stuff and general approach haven't changed a ton.

That could mean he's simply learned to make better pitches, which would obviously be a good thing, but it could also mean he's been fortunate that pitches thrown at roughly the same velocity and roughly the same frequency have created far better results. There's no doubt that Diamond has looked and pitched better, but exactly how much better and the sustainability of his improvement is an interesting question that will require more than 14 starts to answer.

For now I'm cautiously optimistic that Diamond can be a solid third or fourth starter, although admittedly fifth starter was more likely based on his track record prior to rejoining the Twins last month. He throws strikes and keeps the ball on the ground, which is a great foundation for success, and if Diamond can maintain any kind of decent strikeout rate he could be part of the Twins' rotation for a long time. Or at least long enough to make everyone forget Bullock.

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