A potential energy deduction error caused the final lap chaos in Valencia on Saturday, which caused only nine drivers to finish the race, five drivers to be disqualified, and four drivers to retire from the race.

During Saturday’s race, the series saw five safety cars, and as per the FIA rules an energy deduction of 1kwh per minute will be subtracted from the total battery output of 54kwh.

The FIA announced that 19kwh had been reduced from the total of 54kwh. However in the final safety car period, that was caused by Andre Lotterer getting stuck in the gravel at Turn 1 after he came together with Edoardo Mortara, the FIA deducted 7kwh rather than the 5kwh they stated. Therefore the total amount that was deducted from the race was 21kwh.

This is close to half of the battery power being deducted from the cars. But this power is not physically taken out of the cars, which is why we saw the likes of Oliver Rowland and Alexander Sims still ran flat out despite hitting zero percent.

Other drivers like Jean-Eric Vergne tried to cruise around as slow as possible to ensure they didn’t use more power than what they were allowed to.

If you look at the incident energy figures just before the safety car was called, Antonio Felix Da Costa had 22% of usable energy left. Nyck De Vries has 24% and Norman Nato had 20%.

With a 5kwh deduction, it is fairly straight forward to wok out how much percentage each driver should lose. You would do 5 divided by 54, as this is the total amount of usage the drivers have during a race. Then you multiply the answer by 100. The answer is 9.26% of battery usage that the drivers should lose.

The other factor to consider is that the teams still use energy under the safety car but much less.

As the message for the safety car to come in at the end of the lap was called. Da Costa was down to 19%. He had lost 3% from when the safety period had started. However, as it was a 5kwh deduction the same 9.26% energy usage should still be deducted.

Therefore, as the race restarted with 22 seconds left on the clock Da Costa should have had 10% of usable energy remaining and De Vries should have had 13%. Nato on the other hand would have had 6% and would probably had to slow down dramatically to make it to the end.

For De Vries and Da Cosa this would have been enough to reach the chequered flag.

However, after the 5kwh energy deduction took place, 13% of usable energy was actually subtracted from the cars, which is the same as 7kwh.

This is shown by the screenshot where Da Costa now has 6% of usable energy and De Vries has 8%.

Therefore, the wrong amount of energy was deducted from the cars after the final safety car which did last five minutes. If the correct amount of energy was deducted the only driver that would have potentially struggled to finish would have been Norman Nato.