Peer review. After WW II, there was a large rif (reduction in force) in the US military. The Marines decided to use this to their advantage At each level the

Peer review. After WW II, there was a large rif (reduction in force) in the US military. The Marines decided to use this to their advantage At each level they did peer reviews, where the results were one of a) retain at current grade, b) retain, but at lower grade, c) do not retain. This was all done with peer reviews of people at the same level. The result was they retained most of the best people they needed to retain. I've never seen promotion boards or managerial review produce very good results. In largish orgs, you might as well just hold a lottery.