The batting average in Major League Baseball rose slightly in May, but remained at its lowest level in 53 years. Up from .232 in April, May's .239 average was the lowest for the month since 1972, according to New York-based Elias Sports Bureau.

MLB's .236 average for the season through May 31 was the lowest since.229 in 1968－the last season before the pitcher's mound was lowered from 15 inches (38 centimeters) to 10.

Strikeouts, which exceeded hits by 838 in May after topping them by 1,091 in April, have averaged 8.99 per team per game so far this season, on pace to set a record for the 13th consecutive year－and nearly double the 4.77 in 1979.

With so many strikeouts, MLB is under pressure to start enforcing its ban on pitchers doctoring the ball－something New York Yankees ace Gerrit Cole has long been suspected of doing.

Amid accusations that he's among a profusion of high-profile pitchers using illegal substances to gain an edge, Cole was asked during a New York media conference call last week if he uses a sticky substance called Spider Tack. Designed as a grip enhancer for weightlifters, the substance is difficult to detect and reportedly gives pitchers a faster spin rate on balls than more traditional enhancers like rosin.

"I don't know if, uh... I don't quite know how to answer that, to be honest," said Cole, who is 7-3 this season.

According to MLB Statcast data, the Yankees ace had a decrease of 125 rotations per minute on his fastball when he allowed five runs in five innings in a loss to Tampa Bay on June 4.

The three-time All-Star who is in the second season of a nine-year, $324 million contract, has a 2.31 ERA in 14 starts this season. He pitched to a 5-1 record with a 1.37 ERA through his first eight starts, registering 78 strikeouts against three walks in 52.2 innings. Since May 17, he is 2-2 with a 4.30 ERA, with 34 strikeouts against 10 walks in 29 innings.

Minnesota Twins third baseman Josh Donaldson is the latest opponent to call out Cole, labeling the alleged use of Spider Tack "the next steroids of baseball".

"What these guys are doing now is performance enhancing to where it is an actual super glue type of deal," Donaldson told the New York Daily News. "It's not about command. Now, it's about who's throwing the nastiest pitches.

"Is it coincidence that Cole's spin-rate numbers went down after four minor-leaguers got suspended for 10 games? Is that possible? I don't know. Maybe. At the same time, with this situation, they're letting guys do it."

Donaldson referenced a report last week that MLB suspended four minor-league pitchers for doctoring the ball. Those suspensions are seen as a precursor to a crackdown at the major-league level for rules that have been on the books since the 1920s, but are rarely enforced.

MLB rule 3.01 states: "No player shall intentionally discolor or damage the baseball by rubbing it with soil, rosin, paraffin, licorice, sandpaper, emery paper or other foreign substances. The umpire shall demand the ball and remove the offender from the game. In addition, the offender shall be suspended automatically for 10 games."

There have already been six no-hitters this season, thrown by San Diego's Joe Musgrove (April 9), Carlos Rodon of the Chicago White Sox (April 9), Baltimore's John Means (May 5), Cincinnati's Wade Miley (May 7), Detroit's Spencer Turnbull (May 18) and the Yankees' Corey Kluber (May 19).

One more no-hitter would match 1990, 1991, 2012 and 2015 for the most since 1900, one shy of the record eight in 1884－the first season overhand pitching was allowed.