Real life gets in the way of tournament pinball sometimes.

If they qualify but do not return for the bracketed head to head portion they finish in the next highest position (ie, 8 qualifiers, one no shows - they finish 9th, the person that was in ninth is now in the head to head).

If they are in the middle a bracket and leave all further matches involving them are treated as losses.

Knockout/Strike Out event - they are eliminated then and finish with the position of those eliminated that round.

Pingolf - all unplayed holes (machines) get a max score.