Before todays game, they retired Santo jersey number #10.
He is only the third Cub to have his number retired, The other two Cubs are Williams and Banks.
Since the Cubs have existed for so long and have had so many hall of famers, it is really remarkable that they have retired only three numbers.
Ron Santo was the best NL 3b of the 1960s and early '70s. And in the history of baseball, he's probably about the sixth best 3b of all time (after Schmidt, Robinson, Brett, Mathews, and Traynor). Santo belongs in the HOF.