Since 90% or more of all league bowlers couldn't compete in scratch events, you'll see handicap leagues from now until the end of time. And because of this, you'll also see some form of sandbagging, especially when first place pays well. No real need to sandbag if first pays $500 a man, but when you start looking at $1300 or more for first, you start to see it more and more. And these figures are just arbitrary- no research on the exact amounts. We did throw a team out of our league (with the USBC and local association's blessing!) a couple of years ago for sandbagging on the 36th and final week of the season. It took that long to compile enough evidence to show the pattern.
The "good" sandbaggers will do it subtlely, so you don't know they're throwing away pins. The bad ones will just start dumping balls in the gutter and whiffing big spares. Nothing like watching someone stay around the pocket for 2 games, picking up most of their spares, then grab the recap sheet, do a little quick math, then take an area-code sized step to the right and pick off a couple of 7 pins to start the 3rd game.
Experience is something you get immediately after you need it most
Bowl up a Storm!