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ACRO E-mail Archive Thread: TBL or not TBL


Thread: TBL or not TBL

Message: RE: TBL or not TBL

Follow-Up To: ACRO Email list (for List Members only)

From: Salvadori Luca <lsalvadori at>

Date: Tue, 22 Apr 1997 09:51:34 UTC


Hi IAC'ers,

Another bomb is exploding.
TBL is, in my opinion one of the worst problem to be solved in Aerobatics.
It's a nice statistical method, but is almost useless since several other 
ways to compute scores already exist, faster, cheaper and useful for simple, 
real-time computing.
Maybe you remember WAC'96 tales: an Italian pilot posted a protest, won and 
had his scores changed accordingly. TBL was run once more and, suddenly, all 
positions (notably firsts) changed.
The question is: why changing 60th pilot's scores affects the leader?
The answer is: results are correlated by TBL for statistical reason.
To explain statistics essentials, just read this anecdote. I went to Pizza 
Hut with a friend of mine, doctor in mathematics. I ordered a full pizza. He 
didn't order anything and watched me eating. At the end, he said: "OK guy, 
we ate half pizza each!".
Maybe I'm boring, but I say that best pilot wins against all odds. Thus, 
it's better having simple rules everyone can understand, i.e. a simple 
scoring method, computable by paper and pencil, is what we need.
Opponents say "Judges favour their friends". I don't think so, but let's 
admit it. Thus, disregard highest and lowest vote for each figure and 
compute on the others. Noone is so intelligent to help someone this way, 
because there is no time and other judges' score are not available yet at 
the time.
We experienced this method in Italy for years: initially, we were obliged to 
invent something, since we had no contest with sufficient judges and pilots 
to apply TBL. We appreciated the "trick" eventually, since it's simple, fast 
and easy, and all pilots can understand what's on their scoresheet without 
asking Einstein for help.
You don't need a gun to kill a mosquito. Simplest way is the best.
Another two cents...

     Fly High!

     Luca Salvadori
     European Correspondent
     Sport Aerobatics
     Milan - Italy


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