comparison of distribution algorithms

SELECT MemberId FROM bpMember ORDER BY (fromWallet+1)*rand() DESC LIMIT 1:

 #255: selected 560 times
 #40: selected 137 times
 #276: selected 126 times
 #158: selected 56 times
 #73: selected 49 times
 #228: selected 43 times
 #72: selected 20 times
 #254: selected 5 times
 #50: selected 4 times

SELECT MemberId FROM bpMember ORDER BY rand()*5/(1+fromWallet) limit 1:

 #255: selected 100 times
 #276: selected 58 times
 #40: selected 53 times
 #158: selected 51 times
 #228: selected 44 times
 #73: selected 41 times
 #72: selected 41 times
 #50: selected 34 times
 #160: selected 31 times
 #289: selected 30 times
 #273: selected 29 times
 #199: selected 27 times
 #91: selected 27 times
 #198: selected 26 times
 #242: selected 25 times
 #29: selected 24 times
 #281: selected 22 times
 #68: selected 22 times
 #254: selected 21 times
 #7: selected 20 times
 #69: selected 19 times
 #11: selected 18 times
 #203: selected 18 times
 #80: selected 16 times
 #33: selected 16 times
 #159: selected 15 times
 #88: selected 13 times
 #257: selected 12 times
 #290: selected 11 times
 #1: selected 11 times
 #49: selected 10 times
 #17: selected 10 times
 #44: selected 10 times
 #258: selected 10 times
 #22: selected 9 times
 #2: selected 7 times
 #66: selected 7 times
 #122: selected 7 times
 #55: selected 6 times
 #36: selected 6 times
 #173: selected 5 times
 #15: selected 5 times
 #166: selected 4 times
 #184: selected 4 times
 #239: selected 3 times
 #3: selected 3 times
 #70: selected 3 times
 #53: selected 3 times
 #294: selected 2 times
 #161: selected 2 times
 #21: selected 2 times
 #204: selected 2 times
 #14: selected 2 times
 #244: selected 1 times
 #288: selected 1 times
 #230: selected 1 times