I was going through Poliquin’s site and found this tibit -
Another way is to test your 3 R.M and then wait 5 minutes and test for 1 R.M. The most I have ever seen someone do on top of their 3 R.M is 23% more. That is the range that top 7 World Class Olympic lifters will do. Yet, I have seen an Olympic Silver medalist in weightlifting only do 10% more which is the average score. If you can only do 2% more, take up rowing.