Lando Norris clinched his third victory of the season at the Marina Bay Street Circuit, finishing ahead of drivers' title rival Max Verstappen and his McLaren partner Oscar Piastri.
“We shouldn’t have started on the softs, that was a mistake," said Allison.
"If we could turn back time, we would do what those around us did and select the mediums.
“The reasoning was that the soft often allows you to get away from the start abruptly and allows you a good chance of jumping a place or two in the opening laps of the race.
“We had no real expectation before the race that we were going to suffer the sorts of difficulties that we then experienced on the soft rubber.
"We imagined we would get the upside of the soft rubber of getting a place or two, but we didn’t, because that just isn’t the way the starts played out.”