Below is the rule commonly cited as the "Sandbagging Rule":
Rule 17 – Grounds for Disciplinary Action
17a. Unfair Tactics
An individual can be charged with attempting to gain an unfair advantage in league or tournament play
for the following reasons:
1. Directly or indirectly tampering with lanes, pins or bowling balls so they no longer meet USBC
specifications.
2. Misrepresenting an average to gain a greater handicap, or qualify for a lower classification in an
event.
3. Establishing an average below the player’s ability to gain an unfair advantage in handicap or
classified competition.
The question comes down to intent which is where things get tricky. I have seen bowlers use plastic and urethane for the sake of experimentation. They have other equipment, but decide to use plastic or urethane. They may try their best to score, but for 99% of bowlers, using reactive equipment will provide more consistent scores and higher average.
I also see stuff like this when bowlers say they have a "league arsenal" and a "tournament arsenal". I understand if you don't want to risk damage or wearing out or whatever you convince yourself of if you use your best equipment when the stakes are low....
But Rule 17a.3. states you cannot establish an average "below your ability". Does USBC using the term ability remove equipment from the discussion? I also understand in order for it to be sandbagging then you have to use this lower average in a manner to gain an advantage. Perhaps some bowlers don't bowl tournaments. Maybe they don't take advantage of it.
But in my eyes, a bowler should use whatever equipment available and whatever means available to score as high as possible.
This gets really hairy. I know some guys who use plastic during league because they don't like the wide open house shots, and they want to actually have to be somewhat accurate/consistent in order to score. In and of itself, that's admirable. However, if they do that during league, which may cause their averages to be a bit lower, and then they bowl tournaments using "normal" equipment, do we now label them as baggers? Not sure.
It's the same thing with leagues that bowl on tough patterns without officially having them classified as Sport. If guys from those leagues go out and bowl tournaments using the averages from that league, are they a bunch of rotten cheaters? This is tough because, on one hand, you could applaud people for actually trying to challenge themselves on tougher patterns and/or by using low-tech balls, but it isn't really fair to then let them go out and blow the doors off of everyone in a handicap tourney because they average 190 on a tough shot instead of 220 on an easy one.
For me, it comes down to intent. Personally, if I bowled in one of those leagues (non-documented Sport) or chose to use plastic/urethane for the sake of challenging myself, thus resulting in a lower average, I don't think I'd bowl handicap events, or I'd report what I'm doing to the tournament directors so that they could rate me properly.
Just as food for thought, this cuts both ways. When I bowl ABT (now RTB) events, I am forced to use my league average 210+ even though I've probably only averaged about 190-195 on the challenging patterns put out on the tournament circuit. I don't complain because I know that's the price of establishing an average on a THS, but it happens nonetheless.