i voted for viv. but it was purely a personal call. to choose one over the other on "facts and figures" is impossible. there is not much to choose between them in terms of stats.
i would say sachin's best years were from 1995 to 2001. richards' were from 76 to 84. They certainly played awesome knocks before and after these years too, but in my opinion these were the absolute peak years for these champions. and that is long enough to bestow greatness upon anyone in international sport. they were certainly no flash in the pan.
tendulkar faced some of the greatest bowlers in the history of the game - some more often than others - donald, pollock, mcgrath, warne, murali, ambrose, walsh, akram, waqar and akhthar.
but so did richards. he faced lillee, thomson, hadlee, kapil, willis, botham, imran, akram, bedi, chandrasekhar, prasanna and qadir.
both scored hundreds everywhere in either form of the game and did well in all cricket playing countries.
in tests sachin's average in this batting friendly era is 52 (leaving aside the minnows). it compares on par with viv's 50. and richards scored at a faster clip. a SR of 67 compared to sachin's 53 gives an indication of his reputation as the most destructful batter ever.
in ODIs, viv again scored at a faster rate and but with a better average. saching scored more runs and centuries, but in the opening position.
while richards was miles ahead of other greats of his era like gavaskar, chappell, miandad and border sachin had to run neck to neck with the equally great lara. waugh, inzamam, dravid and ponting were the guys immediately after them with ricky looking to join the ranks in the alst three years.
how do we split them?
well, i went for viv because i though he was better than sachin in shepherding the lower order. he somehow gave the confidence of being in control more than sachin, whose reputation for valiant knocks in losing causes dont help him in this poll at all.
small reason. may be statistically incorrect. but as i said, you cant settle this particular argument with numbers alone.