Let's all set PRs this way:
MC1: no NBT allowed, no pipe-jumps woops
DP1: you have to cut the grass where you usually do with NBT, but without boosts
GV1: no NBT allowed, no platform jumps, and you must hit all the bumpers
BC1: no NBT allowed and you must hit all the bumpers
MC2: NBT is allowed but LB is prohibited
CI1: NBT is allowed only for the final dirt cut at every lap, but nowhere else
GV2: two tilehits per lap are mandatory
DP2: every boost, even if non-NBT, is prohibited
BC2: same as BC1, and using the tight part before the series of bumpers is prohibited
MC3: the first boost has to be performed in the first turn, not just after like in the regular strat, and the final boost has to be performed to cut the broken wall part in the sand just before the last turn
KB1: NBT is allowed, but slides aren't
CI2: play the track non-NBT apart from the mud lake cut, NTSC non-NBT side
VL1: destroy all the blocks before entering lap 2 is mandatory
BC3: same as BC1, feel free to take the way you want between the three ones though
MC4: NBT in the last turn is prohibited, but you can use it to cut into the sand's broken wall before, exactly like on MC3. The third boost (after the four pipes) is prohibited too.
DP3: do not jump above the water to cross the second bridge, in any lap
KB2: same as KB1, NBT is allowed, watersliding is prohibited
GV3: non-NBT, no platform jump, and you have to hit both useless bumpers at each lap
VL2: any island jump is prohibited, NBT ans snowsliding are allowed though
RR: no "bad strat" can exist since this track is perfect
I'm pretty sure those contests are worth it, like GV1, BC1, MC2 or VL2. Especially MC2.
This concept is used from courtesy of Andy Lundeen, Inc.:
http://www.mariokart64.com/cgi-bin/yabb2/YaBB.pl?num=1383120187/7#7[ Waiting for Zarkov's Seal of Approval ]