So the USBC has gone to this new 3-teir system to both boost entries and supposedly stop sandbaggers and I'm here to tell you it wont work.  Her is why:

Why have a guy in my area (Tacoma) who rarely bowls over 21 league games a year and averages anywhere between 173 (50+ games) to 184 (24 games), in fact this individual bowls a league every few years, just enough to have an average.  He used to be a 200+ average guy.

Entering this years event his Open average shows as 186 which is a 213 upconverted.  Amazingly this year he manages to shoot less than 1000 for doubles and singles to lower his tournament average to 180 which lowers his converted average to 207 so now he gets to bowl in the middle division.

I should also mention this guy won a classified all events Eagle

So for anyone who believes the USBC will catch sandbaggers, I wouldn't hold my breath.  Cheating will just be on a different level now.

You basically described the rule they just implemented . .

In my opinion, here's a simple way to significantly limit sandbagging for tournaments.

Take the highest book average for the last 3 years or the person's tournament average for that tournament if they have bowled 2 or more years.

It would take someone 3 years of bagging to get a low average, however, if they do really well "magically" at your tournament, you only get away with it for a short period before your average from that tournament becomes the entering average.

Will it eliminate all sandbagging?  No.  But it stops most.

I was suggesting that "ALL" tournaments use it, not just the open.  I know that the FT Worth TX USBC (NCTUSBC) has started tracking averages in their tournaments and if your tournament average is higher than your book, you bowl off your tournament average.  So baggers got 1 year and then they are done unless they want to waste money and bowl bad in the tournament.

And you can even go back more than 3 years depending on how strict you want to be.

One tournament I know of uses a 5 year rolling average for its tournament average.  And if that tournament average is 1 pin higher than book, you use the tournament average. 

In either case, a bagger who has never bowled the tournament gets one shot at it on his low average.  After that, sorry, he/she is on tournament average.