In the following Wikipedia biography on Gary Kasparov, I read the following:
From age 7, Kasparov attended the Young Pioneer Palace in Baku and, at 10 began training at Mikhail Botvinnik's chess school under noted coach Vladimir Makogonov. Makogonov helped develop Kasparov's positional skills and taught him to play the Caro-Kann Defence and the Tartakower System of the Queen's Gambit Declined.
This got me thinking: does the Caro-Kann or the Tartakower System of the Queen's Gambit Declined help with positional skills or was this probably due more to the fact that Makogonov was familiar with it?