Sentiment says that the wily old Dennis Conner, co-leader in Stars & Stripes, still has plenty up his sleeve and will eventually win through. Science, however, says that the group sharing the lead, headed by his former accomplice John Marshall of Pact '95, has the best programme, and that youth will triumph.
Emotion says that the third factor - the all-female crew on Mary - can turn the history books and the sceptics upside-down, despite having won only three races in 17 outings so far. But for that to happen, they will have to have a boat that is markedly faster.
Political rectitude is no compensation for a glaring lack of a commanding presence when it comes to squeezing every last ounce of performance out of this America's Cup-class yacht.
The defenders, in any case, arrange things in such a way that they have as much chance as possible of recovering from setbacks. Marshall and the Young America crew, skippered by Kevin Mahaney, were hit early by a mini- tornado that blew the yacht off its cradle, damaging the hull, and blew the sail loft - plus a few sails - to bits.
America3, with their settled afterguard of JJ Isler, Leslie Egnot and Courtenay Becker-Dey, have been able to hang in by using their two existing boats to test new ideas and designs, especially of keels, which they can transfer to the new boat. They have been reasonably competitive upwind, accepted they were off the pace downwind, but now have a long and thin, state-of-the-art banana-boat.
The fourth round robin, in which all three race each other three times, will decide only the bonus points to carry into the semi-finals, which start on 18 March. The boat with most points takes two points through, the second one, and the third nil.