We review a recent experiment in which pinning centres, composed of discontinuous multiple-in-line damage (MILD), were compared to continuous columnar pinning centres (CCPCs). The methods used, results of the experiment, and the initial steps taken toward a phenomenological theory explaining the unusual results, are discussed. Experimental results show that MILD pinning centres, despite their reduced pinning potential, are far superior to CCPCs. Using MILD pinning, a new record Jc has been achieved in large grain YBCO. The value of Hirr (MILD) is comparable to, or larger, than Hirr (CCPCs). Pinning effects alone, with no modification of texture, weak links or oxygenation of the YBCO, increase Jc by as much as a factor of 17. Splay is expected to further increase this factor. The experimental dependence of Jc on the energy lost by the ion per unit length is approximately reproduced by a phenomenological theory, including only the effects of diminished percolation, critical temperature, and pinning potential.