He played five seasons in Major League Baseball as a left-handed pitcher for the Detroit Wolverines from 1887 to 1888 and the Cleveland Spiders from 1889 to 1891.

He began his professional baseball career at age 20 with the Allentown Peanut Eaters in the Pennsylvania State Association.

[1] After his strong showing at Allentown, a dispute arose between three National League clubs (Detroit Wolverines, Cincinnati Red Stockings, and Indianapolis Hoosiers) over which had the rights to Beatin.

The dispute, referred to as "The Beatin Case", became front page material in the Sporting Life throughout the month of August 1887.

Detroit president Frederick K. Stearns testified and produced telegrams showing that he had closed deals with Beatin and Kinslow on July 20, seven days before Cincinnati claimed to have signed them.

Detroit thus established priority to the players, and the Sporting Life described Cincinnati's case as having "proved decidedly weak."

A report published in The Sporting Life stated: "His slow ball has never been equaled by any pitcher living, it would set such batters as Delehanty, Beckley and Anson perfectly wild, and the little cuss would use it with the bases chock full and a heavy hitter at bat.

Cy Young, Mathewson, Ed Walsh, Mordecai Brown, Addie Joss or any of the artists would gladly separate from $5000 for a loaf ball like Beatin's.

"[10] Beatin pitched a four-hit complete game in his major league debut for Detroit on August 2, 1887, as the Wolverines beat Philadelphia by a score of 10–3.

[15] In 1891, Cy Young emerged as Cleveland's pitching ace, and Beatin sustained arm troubles, spending a portion of the season seeking treatment in Mount Clemens, Michigan.