Cody Bellinger of the Los Angeles Dodgers hits a home run against the Philadelphia Phillies. (Rich Schultz/Getty Images)

There are few milestones in baseball that inspire more excitement than the possibility of a player hitting 60 home runs in a season. There are just eight of those campaigns on the books — Babe Ruth (60 in 1927), Roger Maris (61 in 1961), Mark McGwire (70 in 1998, 65 in 1999), Sammy Sosa (66 in 1998, 63 in 1999 and 64 in 2001) and Barry Bonds (major league record 73 in 2001) — and none in the past 18 years. Giancarlo Stanton hit 59 home runs in 2017, the closest anyone has come to the 60-home-run mark since the league instituted mandatory drug testing in 2006.

Three players this year have a chance to end the drought. Christian Yelich (Milwaukee Brewers), Cody Bellinger (Los Angeles Dodgers) and Pete Alonso (New York Mets) each hit 30 or more home runs before the all-star break, putting Yelich and Bellinger on pace for 57 home runs and Alonso on pace for 53 home runs this season. However, those estimates, especially for Bellinger, could be on the low side for several reasons.

Home runs are being hit at a record rate this season with the possibility of smashing the previous record set in 2017 by as many as 700 home runs. Bellinger also gets the benefit of playing 36 of his team’s remaining 66 games against opponents who give up an above-average rate of home runs per plate appearance. Yelich (27 of 67 games remaining) and Alonso (24 of 69 games remaining) don’t get nearly the same benefit from the schedule. Dodger Stadium is also the 10th best hitter park this season in terms of home run park factor. Miller Park (14th) is average and Citi Field (18th) is below average.

Balls are also traveling further than ever before, perhaps due to what a committee of scientists commissioned by MLB called “a change in the aerodynamic properties of the baseball.” Fly balls are traveling 323 feet, on average, this season, the furthest since Statcast started collecting data in 2015. More fly balls are converted into home runs, too, this season.

Season Average distance Home run to fly ball ratio
2015 315 feet 11 percent
2016 318 feet 13 percent
2017 320 feet 14 percent
2018 319 feet 13 percent
2019 323 feet 15 percent

Add in warmer weather, which typically ushers in an increased home-run rate, and you have all the ingredients necessary for a magical season. For example, from 2006 to 2018, 2.6 percent of plate appearances in March and April resulted in a home run. This April we saw home runs in 3.4 percent of plate appearances. From 2006 to 2018 we saw 2.7 percent of plate appearances in May go deep. This May that rose to 3.6 percent with even higher rates in June and July.

Based on their ratio of home runs to plate appearances in the first half of the season and the estimated plate appearances remaining in 2019, Bellinger and Yelich each have at least an 88-percent chance of hitting 50 or more home runs this year. Alonso has a chance, but it isn’t as robust (40 percent). Bellinger and Yelich are the only players with at least double-digit chances to reach 60 home runs or more this season.

Read more baseball coverage from The Post:

Is anyone the ‘next’ Mike Trout? Probably not.

With ‘45’ on their backs, Angels honor Tyler Skaggs — and then throw a no-hitter

‘Robot’ umpire calls first professional baseball game with one hitch and no controversy

Former MLB pitcher Dwight Gooden arrested for cocaine possession