David Ionovich Bronstein (February 19, 1924 – December 5, 2006) was a Soviet chess grandmaster, who narrowly missed becoming World Chess Champion in 1951. Bronstein (seen here in a picture from 1963) was one of the world's strongest players from the mid-1940s into the mid-1970s, and was described by his peers as a creative genius and master of tactics. He was also a renowned chess writer. To get an idea of how incredibly strong he was, look up his peak average ratings for any range between 1-20 years at http://www.chessmetrics.com/cm/CM2/PeakList.asp?Params=199510SSSSSWS000000000000111000000000000010100
Botvinnik (the WCH Bronstein faced in 1951) wrote that Bronstein's failure in the 1951 WCH was caused by a tendency to underestimate endgame technique, and a lack of ability in simple positions. It's also possible that another reason was pressure by Soviet authorities to let Botvinnik retain his title.* At any rate, in this game Bronstein decides to enter an unusual endgame (Rook + 4 pawns vs 3 minor pieces) against the worst possible opponent: Another Super-GM who is also considered to be one of the greatest endgame players of all time: Vassily Smyslov (Mar 24, 1921 - Mar 27, 2010) who unlike Bronstein beat Botvinnik in 1957 to take away his crown, albeit for only one year. You can also check out Smyslov's amazing performance peaks from 1-20 yrs at the chessmetrics link given above and find several more of his games in my blogs by going to the players index.
* SOURCE: https://en.wikipedia.org/wiki/David_Bronstein