I agree that the penalty should be a graded gap, but only if it's been played recently and has a recent gap pattern. If the gap is lifetime/historical, it won't reflect a recent resurgence; but if the gap can't be recent if it hasn't been recently played.

If it's been played on the current tour, the penalty could be based on the average gap on the tour. If its its been played in the past 12 months but not the current tour, the penalty could be based could be the average gap in the last 12 months, with possibly a penalty or bonus for not appearing yet in the current tour. If it hasn't been played in the last 12 months, the gap could be based on the average historical gap, with possibly an additional penalty or bonus for not having been played in more than a year.

And if we're adjusting the "last seen" penalty, the one-year/12-month cutoff is of course also arbitrary. Maybe it should be the last 30 shows, or the last 3 tours, or the number of shows we'd expect to see within the next year as projected from a moving average of the number of shows seen in past years, or...