Who Has the Increase in Home Runs Hurt the Most?

Whether it be due to juiced ball, launch angle or random variation home runs are being hit at record rates in Major League Baseball. Going back to 1901, the HR/9 record for all of Major League Baseball was 1.18 in 2000 and the top 20 seasons ever are all within 1.00 and 1.18. This year, MLB hitters have averaged 1.28 home runs per nine innings, threatening to shatter the Major League record by the greatest margin since the mark of 1.07 broke the record in 1987 to beat out the previous record of 0.97 in 1961.

On an individual level, 11 players have already hit 20 home runs as of 6/26 and are thus on pace to hit at least 40 each. While they likely won’t all get there, there are another 18 who have hit at least 15, but not reached 20 yet who could also end the season in that range. Last year, only 8 hit 40 and in the record year of 2000 16 players reached the mark (five of whom were strongly indicated to be PED users). Cody Bellinger alone would be on pace for 68 home runs if he were able to play 162 games this year.

There’s no question, home runs are up. My question is, are they up equally throughout the league or have they come at the expense of certain types of pitchers?

For the sake of keeping things as simple as possible, we’ll just look at the change from 2016 to 2017, an overall increase of 0.11 HR/9. Interestingly, the increase has been similar between relievers (from 1.04 to 1.15) and starters (from 1.24 to 1.35). To delve deeper into the issue, here are the top ten pitchers in avoiding the home run in 2016 who have pitched at least 50 innings in 2017.

Least HR Allowed 2016 2017
IP HR/9 HR/FB ERA FIP IP HR/9 HR/FB ERA FIP
Johnny Cueto 219.2 0.61 8.4% 2.79 2.96 100.2 1.61 17.8% 4.20 4.51
Carlos Martinez 195.1 0.69 10.6% 3.04 3.61 100.1 0.90 12.3% 2.87 3.33
Kyle Hendricks 190 0.71 9.3% 2.13 3.20 61.2 1.31 17.6% 4.09 4.50
Tanner Roark 210 0.70 9.4% 2.83 3.79 92.2 1.17 13.3% 5.15 4.31
Jake Arrieta 197.1 0.73 11.1% 3.10 3.52 84.2 1.38 16.5% 4.36 4.09
Martin Perez 198.2 0.82 10.4% 4.39 4.50 82.1 0.98 11.5% 4.70 4.28
Corey Kluber 215 0.92 10.8% 3.14 3.26 72.1 0.87 12.3% 3.24 2.65
Marcus Stroman 204 0.93 16.5% 4.37 3.71 92.2 1.26 20.3% 3.69 4.16
Rick Porcello 223 0.93 9.3% 3.15 3.40 99 1.45 11.9% 5.00 3.96
Jon Lester 202.2 0.93 12.2% 2.44 3.41 96.1 1.12 14.0% 3.83 3.71
Average 205.4 0.80 10.8% 3.14 3.54 87.9 1.21 14.8% 4.11 3.95

Almost unilaterally, there has been an extreme increase in HR/9. In fact, only Kluber has improved his HR rate and only Martinez and Perez along with the Indians ace have kept an HR/9 below 1.00. Not surprisingly, there have been extreme increases in home runs per fly balls down the line, including those three pitchers although the increase has been less significant with the trio. While some of this should be expected in random variation as we’re picking the pitchers who had the most extreme luck in 2016, jumps  from below 10% to over 17%, like in the case of Cueto and Hendricks and the jump from 16 to 20% by Stroman seem a little excessive. Of course, we’ll have to compare these numbers to the unlucky ones to see who has been effected at a greater level.

Most HR Allowed 2016 2017
IP HR/9 HR/FB ERA FIP IP HR/9 HR/FB ERA FIP
Josh Tomlin 174 1.86 17.7% 4.40 4.88 81.1 1.66 15.3% 6.09 4.44
Ian Kennedy 195.2 1.52 12.8% 3.68 4.67 67.1 1.87 14.6% 4.95 5.62
R.A. Dickey 169.2 1.49 14.7% 4.46 5.03 91.1 1.48 15.3% 4.63 5.41
Dan Straily 191.1 1.46 12.0% 3.76 4.88 84 1.22 10.2% 3.43 3.74
Fransisco Liriano 163 1.44 18.8% 4.69 4.89 56 1.29 13.1% 5.46 4.83
Kevin Gausman 179.2 1.40 15.4% 3.61 4.10 80.2 1.56 14.6% 6.47 5.36
Jake Odorizzi 187.2 1.39 12.0% 3.69 4.31 74.1 2.06 18.1% 4.00 5.48
Mike Fiers 168.2 1.39 15.2% 4.48 4.43 78 2.08 23.7% 3.81 5.65
Michael Pineda 175.2 1.38 17.0% 4.82 3.80 87.1 1.75 22.4% 4.12 4.41
Jerad Eickhoff 197.1 1.37 13.1% 3.65 4.19 76.2 1.06 9.7% 4.93 4.18
Average 179.9 1.47 14.9% 4.12 4.52 77.5 1.60 15.7% 4.79 4.91

Unlike the first ten, those who lead the league in HR/9 in 2016 and have pitched at least 50 innings this year have split in two directions. Some, may have been the victim of bad luck, at least as far as home runs are concerned. Tomlin and Liriano in particular allowed incredibly high HR/FB rates, but have come back to more normal amounts. The young Eickhoff also saw an extreme improvement in HR/FB rate and this season actually has a lower HR/9 than nearly all those on the first list.

At the same time, there have been the expected increases in both HR/9 and HR/FB to go along with the increases throughout the league. Mikes Fiers and Pineda as well as Jake Odorizzi have seen a disproportionate piece of this effect. Overall, the increase in HR/9 of 0.13 was incredibly less than the 0.41 increase among those who avoided the home run in 2016.

For a different angle, we know that launch angle and exit velocity have much to do with home run rates (irrelevant of how certain people feel about them), but what about pitchers who provide the power? The ten pitchers below are those with the fastest fastballs in 2016 who have pitched at least 50 IP this year.

Highest Avg Velocity 2016.0 2017
MPH IP HR/9 HR/FB ERA FIP IP HR/9 HR/FB ERA FIP
Carlos Martinez 96.5 195.1 0.69 10.6% 3.04 3.61 100.1 0.90 12.3% 2.87 3.33
Danny Duffy 94.9 179.2 1.35 13.0% 3.51 3.83 68.2 0.52 5.1% 3.54 3.54
Kevin Gausman 94.7 179.2 1.40 15.4% 3.61 4.10 80.2 1.56 14.6% 6.47 5.36
Max Scherzer 94.3 228.1 1.22 11.9% 2.96 3.24 107.2 1.00 11.3% 2.09 2.78
Chris Archer 94.3 201.1 1.34 16.2% 4.02 3.81 104.1 0.78 9.3% 3.88 2.88
Jeff Samardzija 94.3 203.1 1.06 11.9% 3.81 3.85 98.2 1.46 18.0% 4.74 3.49
Robbie Ray 94.1 174.1 1.24 15.5% 4.90 3.76 94 1.05 12.2% 2.87 3.59
Michael Pineda 94.0 175.2 1.38 17.0% 4.82 3.80 87.1 1.75 22.4% 4.12 4.41
Justin Verlander 93.7 227.2 1.19 10.9% 3.04 3.48 87.2 1.03 8.9% 4.42 4.20
Jake Arrieta 93.6 197.1 0.73 11.1% 3.10 3.52 84.2 1.38 16.5% 4.36 4.09
Average 94.4 195.9 1.16 13.4% 3.68 3.70 91.1 1.14 13.1% 3.94 3.77

If nothing else, this list proves that there’s more to pitching than throwing hard as players from both the lack of home run list (Arrieta and Martinez with Perez and Stroman just out of range) and the excessive home run list (Gausman and Pineda) appear again. Again, you have pitchers who have improved as far as allowing home runs (Danny Duffy and Chris Archer being the extremes) and taken a step back (Samardzija and a few already named). Overall, however, there is the slightest decrease in home run rate and home runs per fly ball which, compared to the overall increase, it pretty extreme.

In all, Danny Duffy and Robbie Ray are the most perfect examples of the effect luck can have on pitchers numbers. Based on FIP, both are having similar seasons to their 2016, but drops in HR/FB have lead to extreme drops in HR/9. In particular, Duffy’s looks completely unsustainable after a more normal 2016. These cases have likely skewed the averages for the increased velocity group although the consistency of the elite among the group, Max Scherzer and Carlos Martinez in particular, does make it seem that throwing hard has helped limit some of home run barrage.

Lowest Avg Velocity 2016 2017
MPH IP HR/9 HR/FB ERA FIP IP HR/9 HR/FB ERA FIP
R.A. Dickey 82.3 169.2 1.49 14.7% 4.46 5.03 91.1 1.48 15.3% 4.63 5.41
Josh Tomlin 87.8 174 1.86 17.7% 4.40 4.88 81.1 1.66 15.3% 6.09 4.44
Marco Estrada 88.1 176 1.18 9.9% 3.48 4.15 92 1.47 12.4% 4.89 3.98
Dallas Keuchel 88.3 168 1.07 16.4% 4.55 3.87 75.2 0.71 17.1% 1.67 3.10
Dan Straily 89.2 191.1 1.46 12.0% 3.76 4.88 84 1.22 10.2% 3.43 3.74
CC Sabathia 89.4 179.2 1.10 12.6% 3.91 4.28 75.1 1.08 13.4% 3.46 4.12
Mike Fiers 89.4 168.2 1.39 15.2% 4.48 4.43 78 2.08 23.7% 3.81 5.65
Mike Leake 89.6 176.2 1.02 13.5% 4.69 3.83 98 0.83 12.5% 3.12 3.65
Kyle Hendricks 89.7 190 0.71 9.3% 2.13 3.20 61.2 1.31 17.6% 4.09 4.50
Bartolo Colon 89.7 191.2 1.13 11.5% 3.43 3.99 59 1.68 15.1% 7.78 5.12
Average 88.4 178.3 1.24 13.3% 3.93 4.25 79.5 1.35 15.3% 4.30 4.37

For the sake of fairness, here are the slowest fast balls in the big leagues and, not surprisingly, there are a few repeats from the most home runs allowed list. There are also a couple surprising names including Kyle Hendricks from the least home runs allowed list.

Overall, the slow men have seen an increase in home runs allowed and HR/FB, but it isn’t across the board. Many of the youngish pitchers, like Keuchel, Leake and Straily have actually improved their rates while some of the older fellers like Fiers (32) and Colon (44) have seen extreme increases in home run rates. At the same time, other vets like Dickey and Tomlin have maintained or improved and velocity doesn’t appear to be a factor with those who have seen more balls leave the yard as Fiers is at essentially the same average velocity that he was in 2016 and Colon is miraculously throwing the ball slightly harder.

Taking everything in stride, the sample sizes here are too small to draw major conclusions, but the home run bug has appeared to not be effecting everyone equally. The best of the best (Kuechel, Kluber, Scherzer, Martinez, Perez) have not been particularly effected and those who already gave up a ton of home runs physically couldn’t have given up many more. If they did, in fact, they were likely not qualified for the list as they weren’t able to get to 50 innings this year (this means you Jered Weaver). For the rest, however, whether they throw hard or soft, the home runs are coming for them. If they’ve been lucky in the past, they haven’t been this year. For the league, there has only been an increase of 1% in HR/FB rate over 2016, but this marks the highest rate in baseball history (or at least since they’ve kept track in 2002).

This is the world we live in now. It might not last long (in 2014 the HR/FB rate was just 9.5% with just 0.86 HR/9) , but it certainly appears that all sorts of home run records will be set in 2017 and they will be disproportionally hit against the legions of pitchers who sit between the very best and the absolute worst.

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