Mike Trout, Nelson Cruz Lead Home-Run Surge in 2015

Absent a Carlos Gonzalez-like run of home runs by Mike Trout, Nelson Cruz or another slugger over the last fifty games of the season, major-league baseball looks likely to fall short of a 50-homer season for the fourth time in five years and seventh time in the last nine seasons. Only Chris Davis and Jose Bautista have notched 50-homer seasons since the end of the 2007 season after 23 such seasons between 1995 and the 2007 season. Despite the relative drought in 50 homer seasons, power is up this season over last with multiple players poised to hit more than 40 homers after only Nelson Cruz hit 40 last season.

A month ago, major-league baseball moved to the All-Star break with just over half the season finished. At the time, seven players had at least 25 home runs, giving the league an outside chance of producing a 50-homer season. That group was led by a player who has yet to crack 40 home runs in Giancarlo Stanton. Unfortunately, he had already been injured for several weeks and, despite his 27 home runs, he might fall short of 40 homers again this year. Mike Trout, Albert Pujols, and Bryce Harper were all one behind Stanton with 26 home runs, and J.D. Martinez and Todd Frazier entered the break with 25 home runs.

Since the All-Star break, that group has not quite kept up with their first half totals. As it stands, here is the Home Run Leaderboard after last night’s games.

Player HR
Nelson Cruz 34
Mike Trout 33
Chris Davis 31
Josh Donaldson 31
Mark Teixeira 30
Albert Pujols 30
J.D. Martinez 30
Bryce Harper 29
Todd Frazier 28
Nolan Arenado 27
Giancarlo Stanton 27
Jose Bautista 27


Nelson Cruz has retaken the lead with his home run last night and is currently six home runs short of his MLB-leading total from last season. While nobody is a good bet to hit 50 home runs, baseball should see more than just Cruz crack the 40-homer barrier this season. A 40-home-run season is an accomplishment in any era, but over the last decade, those seasons have become less frequent. From 1996 to 2006, there was an average of 12 40-homer seasons per year with no season dropping below eight players to reach the 40-homer threshold. Since that time, no single season has had more than six players with 40-homer seasons with every season seeing just an average of three 40-homer seasons, including the 25-year low of just one last season.

Home runs have been up so far this season compared to last season. Since 2010, only the 2012 season has seen home runs go out at a more prodigious rate than this season, where home runs have been hit once for every 39 plate appearances, 11% lower than last season’s 44 plate appearances. We are still nowhere near the height of the steroid era, but after last season’s power outage, the power has returned some. The graph below shows the rate of plate appearances per home run over the last two decades (a lower number means more home runs).

MLB PLATE APPEARANCES PER HOME RUN BY YEAR (1)

For those wishing to see a graph where more home runs means a higher point on the graph, the below illustrates the percentage of plate appearances that end in a home run.

MLB HOME RUN RATE BY YEAR

The increase in home runs has had an effect on slugging percentage as well. While both batting average and on-base percentage are within a few points of each other, slugging percentage has increased this year. The increase in slugging is due primarily to home runs, as the rate of doubles is virtually the same as last season and while triples have gone up 6% over last season. Their relative rarity of the latter (roughly once in every 200 plate appearances) leaves home runs as the primary cause of the increase in slugging. Below, the graph shows isolated slugging (slugging minus batting average) in every season over the past two decades.

MLB ISOLATED SLUGGING BY YEAR (1)

The current home-run leaderboard has a mix of young and old as aging sluggers like Nelson Cruz, Mark Teixeira, and Albert Pujols have all put up big numbers this season while youth is being served by Mike Trout, Bryce Harper, and Nolan Arenado. Combining the FanGraphs Depth Charts rest of the season projections along with current totals, the end of the season numbers currently look like this:

Player Updated HR Projection
Nelson Cruz 44
Mike Trout 44
Chris Davis 43
Mark Teixeira 41
Josh Donaldson 40
Albert Pujols 39
J.D. Martinez 39
Bryce Harper 39
Jose Bautista 38
Todd Frazier 37
Carlos Gonzalez 37
Nolan Arenado 36

There are currently five players projected to hit more than 40 home runs, with three more knocking on the door by way of a 39-dinger projection. If six manage to hit 40 out of the park, it would tie 2012 for the most since the 2007 season. The rise is not limited to 40-homer seasons. The graph below shows the number of 40-, 30-, and 25-homer seasons since the advent of the designated hitter in 1973 including projected end of season numbers for 2015.

40- 30- AND 25-HOME RUN SEASONS BY YEAR

There were regularly more 40-homer seasons during the steroid era than 30-homer seasons over the past few years. Baseball has not completely reversed the downward trend that has been happening over the last decade: strikeouts are still very high and run-scoring is up only a little over last season. However, this season has seen more balls leave the yard than the past couple years. As the graphs above show, movements do not happen linearly — sometimes it is up one season, down the next, and sometimes there are prolonged periods of power or eras when it is lacking. We’ve seen a bit of a resurgence this year, but it is too soon to tell if we are in the middle of a movement upwards for home runs or if this year is just a blip similar to the one we saw during the 2012 season.





Craig Edwards can be found on twitter @craigjedwards.

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wobatus
8 years ago

Nice to see some slugging, with a few old-timers (Tex, Cruz, Pujols) and some young blood in there. I also like that it can be called the steroid era and not the expansion, new ballparks, tightly-wound ball, solar spots, random blip era.

rustydudemember
8 years ago
Reply to  wobatus

Why not call it 4 of the best pitchers of all time era (Maddux, Clemens, Johnson, Pedro) – oops! No that wouldn’t fit the narrative.

Mark
8 years ago
Reply to  rustydude

What narrative are you talking about? It’s reality. There was a steroid era. Why on earth would there be a “4 great pitchers era”?

Wobatus
8 years ago
Reply to  rustydude

In my narrative it’s the Steve Trachsel era.

BMarkham
8 years ago
Reply to  rustydude

I call it the bouncy-ball era. If there’s anyone interested in some analysis of why many people think the offensive boom was created by changing the ball (no affliation):

http://owlbb.com/juiced-ball.php

One of the biggest pieces of evidence in favor of this theory is that if you take the average runs per game from ’94 to ’09, each individual season’s runs per game has no more than 10% difference from the runs per game of that era as a whole. Same for ’77-’92.

The game changed relatively suddenly in ’94, and it remained a similar run environment all the way up to 2012, when the called strike zone began to expand.

Other reasons cited in the link questions why expansion would dilute pitching but not also hitting and math showing that smaller parks on their own is a very small factor. They have a sister site where they contend that steroids had little affect on the run environment, but I won’t link that as you can find their site through the original link.