50 in base 64 = y
y in ascii = 121
121 converted from base 3 to base 16 = 10
10 = 3*3+1
3*3+1 in ascii = 051(+)042(+)051(+)043(+)049 = 236
236 in base 26 = 92
92 in base 9 = 112
112 in base 36 = 34
34 in base 64 = i
i is the 9th letter of the alphabet
therefore, 50 = 9
my prediction was correct now give me all your money and fancy hats

everyone knows the default base of English speech is 7, so
50 base 7 = 35 base 10
35 base 7 = 26 base 10
26 base 7 = 20 base 10
20 base 7 = 14 base 10
14 base 7 = 11 base 10
11 base 7 = 8 base 10
so you were off by one, sorry :(

Half life 3 not confirmed