A couple of weeks ago, a bunch of us were doing our usual summer bowling. Anywhere from 3 or 4 old guys up to 8 or 9 old guys get together twice a week and throw 3 or 4 games, just for fun and to keep our old arms loose for the upcoming season.

This particular session, we observed many times a pin would stand on its base and slide from a few inches to as much as a foot, after a hit. Of course, we have all seen this happen during our many years of bowling but during this session, it must have happened 15 or 20 times. Numerous times the rack would not come down due to the off-spot pins. Sometimes, a pin actually moved into another pins spot.

This only happened during this one session, not before nor since.

It happened to guys who threw a mostly straight ball, a big hook, 12 pound balls up to 15 pound balls.

Our only thought was that perhaps the oil machine malfunctioned and it deposited some oil on the pin deck, making it unusually slippery. We could not confirm this theory, however.

The pins were not new and everything else in the house was normal.

Anyone have any ideas as to what might have happened?

When you get oil on the pin deck, pins will get taped and slide because of the oil instead of being knocked over. Friction/no oil on the pin deck will cause the pins to fall over instead of slide when taped by another pin. (Or at least wiggle.)

I ran into that problem at one house during a tournament.  To add to the problem, the front desk had to call to the back to have the pins set up.  After the tournament, I complained with an email and the tournament director insisted they clean pin decks every night.  This year, we didn't have the problem.  I guess maybe they really did clean the decks this year.