Good afternoon batya and thank you for the interesting question!
I have to begin by saying that determining the better chess player is
difficult for a number of factors. For example, Capablanca came back
to play Kasparov, Capablanca would probably be crushed because chess
understanding has advanced over time, and modern chess masters analyze
openings much more deeply than ever before.
However, if I had to give an opinion based off of the game
performances of Capablanca and Kasparov, I would have to say NO,
Capablanca probably would not beat Kasparov.
José Raul Capablanca was a child prodigy, defeating some of the
strongest chess masters by the age of 7. He was undefeated for eight
consecutive years, from 1916 to 1923, a 63-game non-losing streak.
However, in 1924, Capablanca lost his title to Richard Reti.
He was world champion for 6 years and played over 700 tournament
games, winning over 71 percent of the time. He only lost 36 games in
his entire life. His ELO rating has been calculated to be 2725.
Garry Kasparov, on the other hand, became the youngest World Champion,
at the age of 22 years. His ELO rating was 2815 and he is the still
the highest-rated player in history.
* * * * * * * * * *
NOTE: The ELO rating system (put together by Arpad Elo, author of The
Rating of Chessplayers, Past and Present, 1978) is a method for
calculating the relative skill levels of players in two-player games
such as chess. It is said, however, that one could only possibly
measure the strength of a player as compared to his contemporaries.
The top 5 players who have the highest ratings in this system are:
José Raúl Capablanca (with 2725)
Mikhail Botvinnik (2720)
Emanuel Lasker (2720)
Mikhail Tal (2700)
Alexander Alekhine (2700)
Updated lists are issued by the FIDE (Fédération Internationale des
Échecs or World Chess Federation) every three months, and several have
surpassed Capablanca's 2725 (Garry Kasparov achieving the highest ELO
rating of all time).
A later statistician who has used a similar method to Elo's to
retrospectively rate players is Jeff Sonas, who calls his system
Chessmetrics. The players with the highest five-year Chessmetrics
Garry Kasparov (2875)
Emanuel Lasker (2854)
José Raúl Capablanca (2843)
Mikhail Botvinnik (2843)
Bobby Fischer (2841)
If this answer requires further explanation, please request
clarification before rating it, and I'll be happy to look into this
Google Answers Researcher
History of World Chess Champions
( http://www.ku.edu/~kuchess/History_of_chess.htm )
( http://www.chessgames.com/perl/chessplayer?pid=47544 )
( http://www.chessindia.org/WorldChampions_files/joseraul_capablanca.html )
( http://en.wikipedia.org/wiki/Greatest_chess_player_of_all_time )