Michael Schumacher's tyre failure in the German Grand Prix was the result of a high-risk strategy that did not pay off, according to McLaren boss Ron Dennis.
The German finished seventh after his left-rear tyre failed four laps from the end when he was in second place behind race-winner Juan Pablo Montoya.
Dennis said: "It was a marginal tyre. They took a gamble in switching to two stops [instead of three] and it didn't pay off.
"We knew Ferrari's tyres were on the limit. It happened in practice - the left rear is the tyre that takes the high loads here.
"It was a high-risk strategy and they paid the price."
Ferrari were forced into switching from three stops to two at Hockenheim by McLaren's decision to do the same with David Coulthard, Dennis said.
A two-stop strategy puts more strain on tyres, because they have to last for more laps on a heavier fuel load.
Ferrari technical director said the team did not yet know what had caused the puncture.
Coulthard closed in on Schumacher as the race wore on and was catching him for second place when the Ferrari suffered its failure.
Montoya's victory moves him into the world championship reckoning as he is now only six points behind Schumacher.
McLaren, like Montoya's Williams team, use Michelin tyres while Ferrari are on Bridgestones.
McLaren managing director Martin Whitmarsh said: "It was a fantastic drive by David to keep the pressure on.
"We decided to switch to a two-stop and that put the pressure on Michael and the Renaults.
"The Renaults [also on Michelins, but a softer compound than that chosen by Williams and McLaren] were always going to suffer blistering and Michael's tyre failure was a result of being forced to do that strategy."