Did Alfredo Simon get lucky in 2014, or was there a reason for his success?

I think it's safe to say that no one saw Alfredo Simon's 2014 season coming. The Cincinnati Reds gave Simon a spot start, but expected him to slide back into the bullpen once Mat Latos recovered from offseason knee surgery. Instead, Simon allowed one run in seven innings in his first start, earning a second. He fared even better in the next start, allowing a run in eight innings. Before anyone knew it, Simon blazed through the first half of the season, allowing a 2.70 ERA in 18 starts and earning his first All-Star nod.

The second half was a different story. All the signs of regression that dogged Simon throughout the first half -- namely, the .232 BABIP and 4.33 FIP -- came to life after the All-Star break. Simon allowed a 4.52 ERA in 14 second half starts, resulting in a 3-7 record. His FIP remained nearly identical at 4.34, but his BABIP climbed up to .309. After hitting .219/.278/.358 in the first half, opposing batters hit .282/.346/.417 in the second half.

What changed? Other than opposing batters getting luckier -- or, more accurately, Simon's BABIP luck running out -- not much. He allowed a .139 ISO in the first half compared to .135 in the second. His walk rate climbed a bit, but not enough to explain a 70 point difference in on-base percentage. His strikeout percentage dipped slightly, though he actually struck out more batters per nine innings. The big differences were in two stats that have a certain amount of luck attached: BABIP and left-on-base percentage (LOB%).

Was it all luck, though? That's the question we want to answer.

Simon made a big change to his pitch usage last season, and rightfully so, as he moved from the Reds' bullpen to the starting rotation. Oddly, Simon's fastball usage increased slightly from 2013 to 2014. He doubled how often he threw his splitter, and cut his curveball and cutter usage by a considerable percentage.

Despite the big changes in arsenal -- the splitter usage is of particular interest here -- Simon didn't fare much better against left-handed batters. They actually hit for a higher average against him, but did not hit for quite as much power. His walk rate against lefties was also lower in 2014 than 2013, though this isn't necessarily because of how he mixed his pitches. Right-handed batters hit much better against Simon in 2014, compiling a .665 OPS compared to .543 in 2013. His drop in curveball usage may be related to this decline, as he threw the curve just 13 percent of the time against right-handers in 2014.

Why the changes, though, particularly with the off-speed pitches? We examined Simon's off-speed pitch usage (among other things) earlier this week and discovered that he used the splitter most often against lefties. However, the changes he made from 2013 to 2014 weren't because he saw more left-handed hitters. Simon faced 409 left-handed hitters in 818 plate appearances, an exact 50/50 split. In the two years prior, Simon still faced left-handed batters in 47 percent of plate appearances.

Instead, the changes are more likely due to his role as a starter. As a relief pitcher, Simon rarely worked long enough to face hitters more than once in a game. As a starter, Simon was expected to work through a lineup two or three times. This doesn't necessarily explain the uptick in fastball usage -- getting ahead with strike one is imperative no matter when you come into the game -- but the egalitarian use of his three secondary pitches in 2014 could be because of his changed role.

The month-by-month breakdown of Simon's pitch usage is even more interesting, though probably inconclusive if we tried to correlate it to any of his actual results. Long story short: Simon used his cutter more often early in the season, threw all three secondary pitches equally in June and July, and relied more on the splitter during the second half.

While the usage rates may not tell us much about Simon's splits, the effectiveness of those pitches might. The chart below shows the vertical and horizontal break of Simon's pitches in 2014. Each dot represents one month of the season. Most of them are clustered pretty close together, but his cutter (the red dots) showed a definite trend. The red dots farthest right on the chart are for April and May, while the ones on the left represent the second half of the season. This difference seems quite small, but the slight changes in pitch break from April/May to later in the season -- namely, the cutter didn't break as much -- could be part of the reason for Simon's demise.

Unfortunately, this is where the "ineffective cutter" theory all but dies. He buried it down and away in the first half, and continued burying it down and away in the second half. Opposing batters hit much better against the cutter in the second half compared to the first, but they hit better against all of his other pitches too. Well, except the two seamer, which was battered for a .300+ average throughout the entire season.

Whether the subtle difference detailed in the chart above represents a true change in pitch effectiveness or not, there was a significant change in Simon's peripheral numbers from the first to the second half. He threw a slightly higher percentage of first pitch strikes, but opposing batters made contact on 92.3 percent of pitches in the strike zone during the second half, well above their 86.4 percent clip in the first half. This resulted in a drop in his swinging strike rate, from 8.7 percent to 7.5 percent. There is good news, though; Simon's first half whiff rate was much closer to his career norm than the second half.

There doesn't seem to be a concrete answer for why Simon's numbers took a nosedive during the second half. In reality, it was probably a combination of factors: unsustainable BABIP luck, fatigue, a change in pitching arsenal, and familiarity with opponents may have all played a role in why Simon's ERA was nearly two full runs higher after the All-Star break in 2014. This also gives us very little indication as to whether he can repeat his first half success in 2015, though it's probably better to trust conventional wisdom and not expect a breakout season from Simon in his age 34 season.