The equation is as complex as Bermuda's chances of success are unlikely.

In a nutshell, the Island's Under-23 soccer team must first beat Costa Rica in tonight's final Group B Pan-Am match and then wait to discover whether goal difference would open up a path into Saturday's quarter-finals.

Two narrow defeats, 1-0 to Chile last Friday and 2-0 to Brazil on Monday night, have left Bermuda bottom of their group without a point. But with three points awarded for a victory -- yet another change that was sprung on the teams on the eve of this competition -- and two third-placed teams in the three groups qualifying for the quarters on goal difference, there remains an outside chance that Bermuda could advance.

A victory over the Costa Ricans, however, is paramount. And the manner in which they dismantled Chile with three thunderous goals in a 4-1 win on Monday night suggests that will be incredibly difficult.

But while Bermuda coach Mark Trott recognises the enormity of his task, he's not about to throw in the towel.

"We will go all out for victory,'' he said yesterday. "A loss makes no difference to us, no matter how big.

"We will take our chances. We have to gamble and that may leave some holes at the back but we have no option. This is simply a must-win situation.'' Trott can take heart from his youngsters' performance against Brazil which might have had a much different outcome had they capitalised on two or three clear cut chances in the second half.

But they have still to find the net in this tournament and in this evening's do-or-die clash must attack at all costs and be prepared to shoot at every opportunity.

"I wasn't at all disappointed with the way we played against Brazil,'' added Trott. "In fact, the Brazilian coach told me afterwards he thought our boys played very good and were very organised. He was probably suprised that we gave them such a handful.

"One or two breaks didn't go our way. We made two mistakes and they capitalised. But they gave us at least two golden opportunities and we couldn't put them away.'' Having watched Costa Rica twice, Trott fully appreciates their explosive shooting and ability to break from midfield with lightning speed. But there are, he says, chinks in the armour.

"The one thing they do well is attack. But defensively they're not as strong as I thought they would be. They make some silly mistakes. And we've got to make sure we capitalise. "They're not going to be easy. But they can be beaten.'' Tonight's game, again at Tandil's San Martin stadium, should start at 7.00 p.m. Bermuda time, but with both previous kick-offs having been changed without warning, nobody here was taking too much notice of the printed schedule.

Monday night's Group C games in Necochea saw Mexico defeat Trinidad and Tobago 1-0 and Colombia crush Ecuador 5-0.

Mark Trott