Finally got around to trying this and it is great
Previously I was using winzip and zipping the entire .lg folder and burning to dvd.
Acceptable 5 minutes or so to zip the league.
With this little gem the first compression took a few minutes the second was less than a minute. To keep multiple save points I then rename the file to
"xx-xxxxOOTPSAVE.rar" where xx-xxxx is the game number of my current season and the year. So if I've played 50 games in 2015 I name the file "50-2015OOTPSAVE.rar" and burn to dvd. Then rename back to OOTPSAVE on my HD for the next time I want to backup.
DVD's are cheap while backups are priceless