Snatch and clean and jerk attempts, rounded to 1kg, with warm-ups and plates worked out.
Attempt selection is not really a maths problem, but it does have a shape that works more often than not. Three attempts, three different jobs.
It is the weight you could hit on the worst day of your life, in front of a crowd, after a weigh-in that did not go to plan. If there is any doubt at all, it is too heavy.
Missing an opener does not just cost you one attempt. It costs you the next two, because now you are chasing and every decision after it is made in a panic. A conservative opener has never once ruined a meet. Ambitious ones do it regularly.
This is the one that should be a small, confident step. Something you have done in training, or very close to it. Most totals are made here, not on the third.
If the opener flew, you can stretch it slightly. If it felt heavy, do not pretend otherwise.
By now you have a total in the bank and you know how the day is going. This is the attempt that can be a genuine personal best, because missing it costs you nothing you had already earned.
The exception is a qualifying total or a placing. Then the third is arithmetic, not ambition: take what you need, and no more.
Because a calculated one rep max is a guess with decimal places. Attempts built on a number you have never actually lifted are how people open too heavy.
If you do not have a recent single on a lift, use the heaviest clean triple you have done and put that in instead. You will get a conservative frame, which is the right error to make.
Because I would have to reproduce the coefficients from memory, and a scoring formula that is subtly wrong is worse than one that is absent. The arithmetic above is plate maths and percentages, which cannot be quietly wrong.
Use your federation's own calculator for scoring. They maintain it, so it is right.