Bruno Senna says the gap to his Williams team-mate Pastor Maldonado was down to a very small difference in tyre temperature in qualifying for the German Grand Prix.
While Maldonado went on to make Q3 and qualify sixth-fastest, Senna was eliminated in the previous session, setting the 16th best time after the rain fell just before Q2.
But Senna explained afterwards that his intermediate tyres fell out of the ideal operating temperature window, which meant he was powerless to fight higher up the grid.
"It was a bit of a lottery, as it is with these conditions," Senna told AUTOSPORT. "The difference between my tyre conditions and Pastor's was absolutely minimal. It just proves how small the window is with these tyres.
"The smallest difference in temperature can make the biggest difference in laptime, and if you are in the wrong window you are nowhere.
"I absolutely hate making excuses, but sometimes you have to accept that the window is very, very small, and you need to get that right to do anything competitive."
The Brazilian added that the struggles endured by Nico Rosberg and Romain Grosjean, who also fell out in Q2, proved how tricky it was to get the intermediate tyres working.
"Rosberg was behind me," he said. "Grosjean was quick yesterday but he struggled today. It's not really a situation that rewards driving, it's more luck. If you are in the right window then suddenly you are fast.
"We were competitive in the dry in Q1 so we can look forward to the race. But starting from where I am, instead of scoring 10 or 12 points, we can score one or two maximum. You can only overtake so many cars."