OCBUA

1970: The Worth Bat Co. produced the first aluminum bat to hit the market.

1972: Worth produced its first official one-piece Little League model.

1974: The first official NCAA bat was Worth's "Tennessee Thumper."

1989: NCAA imposed a rule that states the length of bat in inches may not exceed by five units the weight of bat in ounces. For example, a 34-inch bat had to weight at least 29 ounces.

1993: Little League received reports of an average of 145 pitchers hit by line drives per year and introduces a Bat Performance Factor (BPF) rating system measuring the exit speed of a ball off the bat. Since the ruling, reports of pitchers hit by line drives has dropped to 20 to 30 per year. "Considering there are more than a million Little League games played each year, with hundreds of millions of pitches, this safety record is nothing less than outstanding," Little League announced in a 2007 press release.

June 6, 1998: Southern Cal defeated Arizona State in championship game of College World Series, 21-14. The NCAA begun investigating ways to curb the offensive explosion of the game.

August 1998: New NCAA rules shrunk bat barrels to 2 5/8 inches or less in diameter and changed the weight-to-length correlation to three units. The BESR (Ball Exit Speed Ratio) protocol required the exit speed of a ball shot at 70 mph toward a stationary bat to be no greater than 94 mph.

March 14, 2007: The New York City Council voted to ban the use of metal bats in high school games in the city. The Public School Athletic League also adopted a pitch count rule to protect the arms of its pitchers.

Spring 2007: Offensive numbers begin to rise again as college players started swinging high-powered composite bats. By 2010, home runs had increased per team per game by 0.26 and teams averaged 0.88 more runs per game than they did in 2007.

June 2009: Twenty of the 25 game-used bats tested during the NCAA Division I playoffs failed the BESR (Ball Exit Speed Ratio) test the bats had passed immediately following production. NCAA begun investigating the performance of composite bats improving over time.

Sept. 2009: The NCAA placed a moratorium on composite bats until they meet BBCOR (Batted Ball Coefficient of Restitution) standards.

Jan. 1, 2011: The NCAA adopts the BBCOR and ABI (Accelerated Break-In) standards that took into account the inertia provided by a moving bat and the tendency for composite bats to become more powerful after repeated use.

Approved bats

For lists of approved bat models, please visit the following websites:

http://www.littleleague.org

http://www.ncaa.org/baseballbats

Washington State University sports science laboratory: http://www.mme.wsu.edu/~ssl/

UMass-Lowell baseball research center: http://m-5.eng.uml.edu/umlbrc/index.htm

Injury rates

• 78 percent of all high school baseball injuries are suffered at five spots on the diamond. In order: first base, home plate, second base, third base and the outfield. The sixth most common location for injuries is the pitcher's mound.

• In competition, base runners are injured more often than pitchers.

• 44 percent of all baseball injuries are specifically to the shoulder, arm, elbow, wrist and/or hand; 23 percent of baseball injuries are to the head and face.

• Little League International has tracked injury statistics since the early 1960s. There have been eight fatalities in Little League from a batted ball and six of those occurred with wood bats. The two non-wood fatalities happened in 1971 and 1973.