By Anthony Zilis In a matter of days, tennis champion Roger Federer may win his 15th Grand Slam tennis tournament, passing Pete Sampras for most all-time. If he wins his sixth Wimbledon, Federer's accomplishments will, undoubtedly, vault him into discussions including the top sports champions of all time. Comparisons will be made to Tiger Woods, Bill Russell, Michael … [Read more...] about Roger Federer’s Window Closing?