Until the 1960s, a fair number of gliders were able to do well in open competition, with smaller-span types occasionally beating larger but more cumbersome types. The composite revolution caused a shake-down, further aggravated when the ASW 22 and Nimbus-3 were introduced in 1981, after which the Open Class for a while became the exclusive preserve of only two manufacturers. The World Gliding Championships of 2012 brought into competition new designs, some of significantly lower wingspan, which flew successfully against "traditional" (wingspan 28 m+) machines of this class.