2004 NFHS Softball Rules Book, Rule 1-5-4 states: "Effective January 1, 2004, the bat shall meet the Amateur Softball Association (ASA) 2004 Bat Performance Standard."
ASA 2004 PERFORMANCE STANDARD
ASA has adopted a new bat performance standard, effective January 1, 2004. This change has been made in light of recent scientific developments. Much of the research leading to the new bat standard and the new ASTM test method has been funded by ASA. ASA has determined that this change is necessary because some of the highest performing bats on the market are adversely affecting the character and integrity of the game and rendering a player's performance more a product of his/her bat than his/her individual skill.
The ASTM F1890 test method is no longer the industry standard, even though some softball associations continue to rely on this test method. ASTM has just recently developed the ASTM
F2219 test method. The most recent version of F2219 is available at www.astm.org - click on "standards." This test method provides a number of improvements over the old ASTM F1890 test method. For example, F2219 allows bats to be tested in the lab at a much higher speed, including speeds actually found in the field of play. It also places tighter tolerances on testing procedures, such as the softballs that are used in conducting the bat test. ASTM F2219 allows the testing to be done at the "sweet spot" of the bat - regardless of where that point is along the barrel of the bat.
The ASA 2004 bat standard relies on the swing speed of the batter. ASA has learned and now takes into account that a batter's swing speed is more dependent on the distribution of the weight across the length of the bat than just the total weight of the bat alone. This weight distribution feature is often referred to as the bat's moment of inertia, and is incorporated into the new 2004 standard. The 2004 standard is also based on more accurate information about the speeds involved in the "bat-ball collision," which are swing speed of the bat and the pitch speed of the ball.
The 2004 bat standard has a maximum batted ball speed (BBS) limit of 98 mph when tested according to the ASTM F2219 test method (as approved for balloting). Even though this limit is numerically higher than the ASA 2000 bat performance standard, in science and in practice the 2004 bat standard is actually a reduction compared to the 2000 bat standard. The F2219 testing is done at higher speeds than under the old F1890 standard. As a result, some bats that satisfied the old ASA standard of 125 fps will not pass the new 98 mph standard. Bats that do not satisfy the ASA 2004 Bat Performance Standard will not be permitted in NFHS play, effective January 1, 2004. Bats that satisfy the ASA 2004 Bat Performance Standard will be authorized to display a new 2004 ASA certification mark. Older bats that pass the new standard will be added to the list of approved bats and will be permitted for NFHS play.