The GI Kentucky Derby picture may seem polarized by two more charismatic talents, but any neutral who ekes a living from bloodstock now has an alternative rooting interest. For among the colts entering those 20 coveted gates, the first Saturday in May, there will be no better symbol than Stronghold (Ghostzapper) of what it takes to last the course in the appallingly expensive, demoralizing, perplexing, maddening and addictive vocation of Thoroughbred breeding. The GI Santa Anita Derby winner carries the silks of Eric and Sharon Waller, who bred his third...