Sabermetricians have attempted to find different measures of pitching performance that exclude the performances of the fielders involved. One of the earliest developed, and one of the most popular in use, is walks plus hits per inning pitched (WHIP), which while not completely defense-independent, tends to indicate how many times a pitcher is likely to put a player on base (either by base-on-balls, hit-by-pitch, or base hit) and thus how effective batters are against a particular pitcher in reaching base. A more recent development is the creation of defense independent pitching statistics (DIPS) system. Voros McCracken has been credited with the development of this system in 1999. Through his research, McCracken was able to show that there is little to no difference between pitchers in the number of hits they allow, regardless of their skill level. Some examples of these statistics are defense-independent ERA, fielding independent pitching, and defense-independent component ERA. Other sabermetricians have furthered the work in DIPS, such as Tom Tango who runs the "Tango on Baseball" sabermetrics website.