Every year, a number of starting pitchers seemingly come out of nowhere to become significant contributors at the major-league level. Sometimes, like in the case of, say, Jacob deGrom, the sudden evolution at the major-league level is real and sustainable. In the case of the majority of these short-term success stories, the league adjusts, the pitcher is unable to, and either disappears from the major-league scene or settles into a lesser role.

This spring, Mariners right-hander Erasmo Ramirez was out of options, and was designated for assignment off of the 40-man roster. In these types of situations, a club is lucky to receive a fringe prospect in return. In this case, however, the Mariners were able to acquire the Rays’ version of Ramirez in lefty Mike Montgomery. His services were required at the major-league level shortly thereafter, and in his first seven starts, Montgomery was a revelation, posting a 1.62 ERA. In his last seven starts, however, he’s been more like the Book of Revelation, unfurling a 7.99 ERA. Which is the real Mike Montgomery, and might he still be someone the Mariners can be excited about moving forward? Is there really that a stark a difference between the Before and the After Model in this comparison test? Let’s take a look at Montgomery’s 2015 batted-ball data and make some observations.

Back in the days when the Royals were heralded for possessing the best minor-league system in the game, Montgomery was one of their crown jewels. The 36th-overall selection in the 2008 draft hit the ground running, and experienced significant success at both Class-A levels in his first full pro season, despite not turning 19 until July 1. Each year, I compile my own ordered minor-league lists of top full-season-league position-player and starting-pitcher prospects based on performance and age relative to league and level. These basically serve as follow lists, with the orders then tweaked based on traditional scouting methods. Montgomery made my list three straight years between 2009 and -11, with a peak ranking of #35 in 2009. Baseball America arguably loved him even more, placing him on their Top 100 list, which encompass position players and pitchers, after each of those three seasons, as high as #19 and no lower than #39 overall.

Then the old TINSTAAP adage took hold, and Montgomery stagnated at the Triple-A level for over three full seasons, drifting from Kansas City to Tampa Bay in the James Shields/Wil Myers deal after the 2012 season. No one has had more success in turning young minor-league pitching prospects into cost-controlled major-league pitching assets than the Rays, and they got absolutely nowhere with Montgomery, eventually dispatching him to Seattle for Ramirez this spring.

Today, we’ll take a look at Montgomery’s plate-appearance frequency and production by ball-in-play (BIP) type data, both for his entire body of major-league work, and for the “good” and “bad” halves of his season. Is his performance over the last month-plus something we should have seen coming? First, the frequency information:

FREQ – 2015 Montgomery % REL PCT K 17.2% 85 35 BB 9.0% 120 95 POP 1.6% 50 15 FLY 28.4% 93 26 LD 19.5% 93 26 GB 50.6% 112 84 ———— ———— ———– ———– 1st 7 Starts % REL PCT K 16.1% 80 19 BB 6.7% 90 55 POP 2.0% 63 17 FLY 32.9% 108 69 LD 19.5% 93 26 GB 45.6% 101 59 ———— ———— ———– ———– Last 7 Starts % REL PCT K 18.5% 92 45 BB 11.7% 156 99 POP 0.9% 28 1 FLY 22.6% 74 8 LD 19.6% 93 27 GB 56.9% 126 96

The full-season data is on top, followed by his first seven starts in the middle, and the last seven on the bottom. We’ll start with his “good” starts. Even when he was getting good results, Montgomery’s strikeout and walk (K and BB) rates were quite ordinary, leaving him relatively little margin for error. His 16.1% K rate ranked in the 19th percentile, his 6.7% walk rate was solid, but in the company of major-league starting pitchers, was only in the 55th percentile. His BIP distribution during his first seven starts was rather vanilla: his liner rate percentile rank was low at 26, but his fly-ball percentile rank (69) was actually a touch higher than his grounder percentile rank of 59. He was not a pop-up generator, with a low percentile rank of 17. The combination of below average K/BB skills along with no go-to pop-up or grounder tendency didn’t bode well for his future.

In his last seven starts, Montgomery’s K rate increased to 18.5%, though his percentile rank remained slightly below average at 45. His BB rate spiked to 11.7%, however, quite a bit higher than any current ERA-qualifying starter, good for a 99 percentile rank. That further eroded his margin for error, which he greatly needed, as it turned out. Interestingly, Montgomery’s BIP frequencies look a good bit better over his last seven starts. His liner rate remained low (27 percentile rank), and his grounder rate spiked to 56.9%, for a 96 percentile rank. His pop-up rate almost literally dropped off of the page, to a 1 percentile rank, but that’s acceptable given his extreme grounder rate.

Putting the two seven-start stretches together, you have a pitcher with a poor K/BB foundation (35 and 95 percentile ranks), but a clear ground-ball tendency (84 percentile rank). The low liner rate (26 percentile rank) would appear to be likely to regress upward moving forward from today. Based on the frequency data alone, one could make the argument that with some improvement around the K especially the BB margins, one might be able to see a future for Montgomery as a low-end ground ball-inducing starter, assuming his BIP authority allowed figures were somewhat under control. To get a better feel for that piece of the puzzle, let’s move on to Montgomery’s production allowed by BIP-type data, presented in the same manner as the frequency data:

PROD – 2015 Montgomery AVG OBP SLG REL PRD ADJ PRD ACT ERA CALC ERA TRU ERA FLY 0.190 0.524 103 102 LD 0.667 1.246 128 116 GB 0.205 0.214 63 104 ALL BIP 0.301 0.494 95 104 ALL PA 0.244 0.313 0.400 100 108 4.14 3.86 4.17 ———— ———— ———– ———– ———– ———– ———– ———– ———– 1st 7 Starts AVG OBP SLG REL PRD ADJ PRD ACT ERA CALC ERA TRU ERA FLY 0.107 0.179 19 80 LD 0.594 0.938 86 112 GB 0.115 0.115 19 88 ALL BIP 0.224 0.320 46 92 ALL PA 0.185 0.241 0.264 52 94 1.62 2.02 3.62 ———— ———— ———– ———– ———– ———– ———– ———– ———– Last 7 Starts AVG OBP SLG REL PRD ADJ PRD ACT ERA CALC ERA TRU ERA FLY 0.357 1.214 474 157 LD 0.760 1.640 194 120 GB 0.304 0.321 140 123 ALL BIP 0.402 0.723 185 123 ALL PA 0.317 0.398 0.570 179 126 7.99 6.91 4.87

The actual production allowed on each BIP type is indicated in the batting average (AVG) and slugging (SLG) columns, and is converted to run values and compared to MLB average in the REL PRD column. That figure is then adjusted for context, such as home park, team defense, luck, etc., in the ADJ PRD column. For the purposes of this exercise, sacrifice hits (SH) and flies (SF) are included as outs and hit by pitchers (HBP) are excluded from the on-base percentage (OBP) calculation.

Lot to address here. Let’s tackle those first seven starts, in the middle portion of the table, first. One cannot overestimate the amount of good fortune received by Montgomery over that span. He allowed a paltry .107 AVG-.179 SLG on fly balls in his first seven starts, for an actual REL PRD of 19. Adjusted for context, that figure moves much closer to league average, at 80. Similarly, Montgomery allowed just a .115 AVG-.115 SLG on grounders, also for an actual REL PRD of 19, which when adjusted for context, creeps even closer to league average at 88. Putting it all together, his actual REL PRD on all BIP, or Unadjusted Contact Score, in his first seven starts was 46, off the charts low. After adjustment for context, his ADJ PRD, or Adjusted Contact Score, is a much more ordinary 92, and that’s with a low liner rate that is likely to regress moving forward.

Add the K and BB (31/13 over 50 IP) back to his Adjusted Contact Score data, and Montgomery’s “tru” ERA over his first seven starts was 3.62, way higher than his actual and component ERAs of 1.62 and 2.02. No one should have been fooled by his first seven starts; even with all cylinders clicking, Montgomery was essentially a league-average starting pitcher.

It’s a much different story in the last seven starts. Regression has punched Montgomery in the gut. He has allowed .357 AVG-1.214 SLG on fly balls (474 actual REL PRD), .760 AVG-1.640 SLG on liners (194) and .304 AVG-.321 SLG (140) on grounders. Combined, that’s an amazing 185 Unadjusted Contact Score on all BIP. This time, context works in his favor, reducing his fly ball, liner and grounder Contact Scores to 157, 120 and 123, respectively, with an overall mark of 123.

Add the K and BB back (30/19 over 32 2/3 IP), and his “tru” ERA over his last seven starts is 4.87, way below his actual and component ERAs of 7.99 and 6.91. Remember, Montgomery had a much better BIP mix in the last seven starts as compared to the first seven. Regression and BIP authority both have caught up to him of late, in a big way.

Overall, his Adjusted Contact Scores on each BIP type (102, 116 and 104 for fly balls, liners and grounders, respectively) have settled in higher than league average levels. He has still been very lucky on grounders (actual 63 REL PRD), the main reason that his Unadjusted Contact Score of 95 is still better than the adjusted mark of 104. Overall, his “tru” ERA of 4.17 is magically almost identical to his actual mark of 4.14. His recent collapse is clearly something that should have been expected. His true talent has moved by only 1.25 ERA basis points between the two groups of starts, while his actual ERA has exploded by 6.37 basis points.

There has been spike in the average batted-ball velocity allowed by Montgomery over the last seven starts, from 87.9 mph in the first seven to 92.1 mph in the last seven, for an overall average of 89.7 mph, which is over a standard deviation higher than the average of AL ERA qualifiers at the All-Star break.

He’s allowed average fly-ball velocity of 91.5 mph for the season (91.4 mph in the first seven starts, 91.6 mph in the last seven). That’s over a full standard deviation worse than the AL ERA-qualifier average at the All-Star break. His average liner-velocity allowed of 96.1 mph (up from 94.5 mph to 98.1 mph) is over two standards deviations higher than average. His average grounder-velocity allowed of 86.8 mph (up from 84.1 mph to 89.7 mph) is over a half standard deviation higher than average. At no point, not even during the heady days of his earlier outings, was Montgomery allowing weaker than league average contact, and presently, he’s allowing harder overall contact, by quite a margin, than any other AL ERA qualifier had as of the All-Star break. He also has allowed hitters to pull the ball against him at a higher than league average rate, the pull rate increasing as the season has progressed.

So what do we have? On the positive side, Mike Montgomery has a clear ground-ball tendency. So did Trevor Cahill. A grounder tendency doesn’t do you much good if you are allowing harder-than-average grounder authority, as Cahill before and Montgomery now have both done. Ground-ball pitchers don’t typically induce pop ups, but Montgomery has taken that to an extreme low, especially of late.

If anything, we should only expect further regression, as Montgomery’s liner rate has remained low, even throughout his massive recent struggles. His swinging-strike rate of 8.6% is nearly a half standard deviation below the AL ERA-qualifier average (though it has ironically been higher in his last seven starts), so the K rate likely is what it is. His BB rate will likely stabilize at a lower rate than his recent spike, but it won’t ever be a strength. Montgomery is what he was: a 7th starter who was a decent return for what Erasmo Ramirez was allowed to become, but not what he was in the first place and is now.