In my estimation, there are three types of breakout seasons:Prospect who develops as he gains experience in his first, second, or third year (Matt Harvey, Jose Fernandez, Jeff Locke)Player who blossoms just after losing prospect status anywhere in their fourth through sixth seasons (Derek Holland, Anibal Sanchez, Mike Leake)Veteran with a consistent, usually average or above average, career track who unexpectedly has a career year (or years) in their 30s (Hiroki Kuroda, A.J. Burnett, Bartolo Colon)Of the three groups, I’m most intrigued by group 2, and three pitchers from this class are the subject of today’s post. Why did they struggle for more than a couple seasons and fail to live up to their potential? What changed during their breakout seasons? Can they keep up this new level of performance through the primes of their careers?Let’s take a quick look at Holland, Sanchez, and Minor on a case-by-case basis.Derek HollandYearAgeTmWLERAGGSIPHRBBSOERA+WHIPBB/9K/9K/BB200922TEX8136.123321138.12647107761.503.17.02.28201023TEX344.08141057.1624541101.318.104.22.16801124TEX1653.953232198.022671621121.353.07.42.42201225TEX1274.672927175.13252145922.214.171.124.79201326TEX863.182222147.011421351331.2126.96.36.199Key Breakout Stats: 3.18 ERA, 3.21 K/BB, 11 HRWhat Changed? Frankly, this comes down to two factors — walks and homers. Holland’s walk rate has dropped every season since his 3.8 BB/9 and 9.5 BB% in 2010 to 2.6 BB/9 and 6.8 BB% this season, and his 7.2% HR/FB rate is half what it was last season (15.2%).What Stayed the Same? Holland’s batted ball profile remains largely unchanged. He still induces grounders a tad more than flies (1.13 GB:FB this year, 1.15 for his career), and his 23.8% line drive rate is higher than his career average (19.5%).Will It Continue? A 7.2% HR/FB rate while playing half of your games in Arlington is too optimistic. Honestly, something in the 10-11% range is where we should expect Holland to settle, and that will push his ERA closer to 3.50. Still, 2013 marks the first time in Holland’s four-and-a-half years as a major league starter that he’s combined a walk rate under 3.0 BB/9 and a strikeout rate over 8.0 K/9, and that’s definitely an encouraging sign for him going forward.Anibal SanchezYearAgeTmWLERAGGSIPHRBBSOERA+WHIPBB/9K/9K/BB200622FLA1032.831817114.19467215188.8.131.52.57200723FLA214.806630.031914922.075.74.20.74200824FLA255.57101051.272750781.5184.108.40.206200925FLA483.87161686.01046711111.5220.127.116.11201026FLA13123.553232195.010701571171.318.104.22.16801127FLA893.673232196.120642021061.222.214.171.12401228TOT9133.863131195.220481671081.2126.96.36.199201329DET972.591818111.053512016188.8.131.52.43Key Breakout Stats: 2.59 ERA, 1.18 WHIP, 9.7 K/9What Changed? Sanchez finally got some luck. On the surface, claiming Sanchez’s breakout is fueled by luck doesn’t seem to do justice to how great he’s been this season, but his peripherals this season aren’t that different than what he posted in 2011. His K% in 2011 was 24.3 versus 26.3 this year, his BB% in 2011 was 7.7, identical to this season, and his batted ball profile is almost identical as he posted a 1.24 GB:FB ratio in 2011 versus 1.28 this year. The key difference is the home runs allowed: 0.92 HR/9 in 2011 versus just 0.41 this year. That decrease can be attributed entirely to Sanchez’s HR/FB rate, which at just 5.2% is half what we saw in 2011 (10.4%).What Stayed the Same? Pretty much everything. Both 2011 and 2013 show huge leaps in strikeout efficiency as Sanchez struck out over a batter per inning in both seasons compared to just 7.2 and 7.7 K/9 in his two other full seasons, but as I listed in the section above, a lot of what Sanchez has done to breakout this season really began in 2011.Will It Continue? As with Holland, a low HR/FB rate can turn a good season into a great one. It’s unlikely, though not impossible, for Sanchez to reproduce that single-digit HR/FB rate again next year, but it’s much more likely he regresses to a league-average rate (around 10%). Still, given his great strikeout rate and sub-3.0 BB/9, that means an ERA just over 3.00. That’s exactly where I expect Sanchez to be over the next few years — somewhere in the 3.00-3.25 range. His xFIP this year is 3.09, and in 2011 it was 3.25, lending credence to that projected range.Mike LeakeYearAgeTmWLERAGGSIPHRBBSOERA+WHIPBB/9K/9K/BB201022CIN844.232422138.1194991961.4184.108.40.206201123CIN1293.862926167.223381181021.182.06.33.11201224CIN894.583030179.02641116911.3220.127.116.11201325CIN1042.592121135.21432831518.104.22.168.59Key Breakout Stats: 2.59 ERA, 1.17 WHIPWhat Changed? With a 19.4% line drive rate, Leake has gone a good job this year of avoiding hard-hit balls. In 2010 his line drive rate was 20.6%, and last year it was 25.4%. The drop in line drives has primarily led to a rise in ground ball rate, which at 49.3% is the highest it’s been in the last three seasons. Leake has also allowed fewer homers this year, just 0.93 HR/9. His previous career best was 1.23 HR/9. This drop can be attributed to a decrease in HR/FB rate, which has fallen to 10.6%.What Stayed the Same? Leake is actually posting a career-low strikeout rate at just 5.5 K/9 with a 14.9 K%, and his 2.1 B/9 is the same as it’s ever been. He’s also allowing fly balls as often as ever, just over 30% of the time.Will It Continue? Nope. I doubt Leake is relied upon heavily in many fantasy circles because of his pitiful strikeout rate, but his 2.59 ERA and 1.17 WHIP over 135.2 innings is good enough to have him owned in just about all formats. Unfortunately, his season thus far is a mirage. Leake’s 83.1% strand rate is about 10 points higher than the league average, and like HR/FB rate, strand rate is one of those peripheral stats you just don’t get better at. You regress to the league average or get lucky again (usually). Leake’s also been the beneficiary of a .268 BABIP this year. While low, it’s not ridiculously low given his batted ball profile, which I’d say suggests he should have about a .285-.290 BABIP (just eyeballing it). Leake’s 3.98 FIP and 3.99 xFIP are much more indicative of the kind of pitcher he is. The fall is coming, and it might come before this season ends.