Del Gainer with the Boston Red Sox
|Born: November 10, 1886
Montrose, West Virginia
|Died: January 29, 1947
Elkins, West Virginia
|Batted: Right||Threw: Right|
|October 2, 1909 for the Detroit Tigers|
|Last MLB appearance|
|September 30, 1922 for the St. Louis Cardinals|
Dellos Clinton Gainer (November 10, 1886 – January 29, 1947), nicknamed "Sheriff," was a Major League Baseball first baseman who played 10 seasons in the Major Leagues. In his 10 seasons, Gainer won two World Series rings with the Boston Red Sox and was teammates at different times with Ty Cobb, Babe Ruth, Tris Speaker, and Rogers Hornsby.
Born in Montrose, West Virginia, Del Gainer played for the Detroit Tigers from 1909 to 1914. In his first full season (1911), Gainer hit .302 in 70 games. The 1911 Tigers opened the season with a phenomenal 21–2 record, as Gainer was credited with making an impact. However, a mid-season wrist injury took Gainer out of the lineup. Though the Tigers were 63–32 on August 1, Gainer had to watch from the bench as the Tigers suffered their first losing month of the season, going 11–16 in the month of August and ending up 13½ games behind the Athletics at season's end.  
In 1912, Gainer struggled at bat, hitting .240 in 52 games. In 1913, Gainer got the job as the Tigers starting first baseman, hitting .267 in 105 games. After only 1 game in 1914, the Tigers placed Gainer on waivers—which gave Gainer his shot at back-to-back World Series championships with the Red Sox.
In May 1914, Gainer was selected off waivers by the Boston Red Sox from the Tigers. He played five seasons in Boston from 1914 to 1917 and 1919.
In 1915, Red Sox manager Bill Carrigan chose to platoon Gainer with Dick Hoblitzel at first base. It was a great success, as the two had a combined OPS+ of 131, helping the Red Sox won 101 games and the pennant. 
Gainer played in 82 games and hit .295 with 8 triples and 29 RBIs for the 1915 World Series championship team from Boston. He had the 2nd highest batting average of players who had at least 100 at bats for the Red Sox—trailing Tris Speaker. He went on to hit .333 and scored a run for Boston in the 1915 World Series.
Gainer also played for the 1916 World Series champions and got a key pinch-hit single in Game 2 of the 1916 World Series. His hit came in the 14th inning of Game 2, ended the longest World Series game in history, and won the game for pitcher Babe Ruth.  In the 1915 and 1916 World Series, Gainer hit a combine .500 getting 2 hits in 4 at-bats.
In 1917, Gainer hit .308 and had the second highest batting average on the Red Sox, trailing only Babe Ruth. Gainer and Ruth were also the only Red Sox players with a slugging percentage above .400.
After two seasons away from the Major Leagues, Gainer played 43 games for the 1922 St. Louis Cardinals. Gainer ended his Major League career in style, hitting a 3-run home run in his last at bat on September 30, 1922. 
- BR Bullpen
- Article: "Chris Shelton Meet Del Gainer"
- Del Gainer at Find a Grave