Mark McGwire gave it a try at the Western Open but an opening round 82 really hurts. What I find amusing about his 82 is that he said "I think I hit enough shots out there so they knew I basically have a game." Hello! Earth to Mark! This is golf, less is better. You hit more than enough shots out there, you hit too many. If you had hit less shots out there we would have known that you have a game.
These former athletes with too much money and too much free time should stick to playing in Celebrity Tour events. Look at Rick Rhoden, he's a great golfer, but he knows his limits. He sticks to beating John Elway and other athletes and celebrities out there, not the guys on the PGA or Champions Tour. Mark McGwire you'll be a good golfer one day, but don't think you can compete with guys who have been playing at the professional level for many years, you'll just embarrass yourself.
I do believe former pro athletes can become very good golfers in shorter periods of time then the rest of us for several reasons. First they retire at a young age and have nothing else to do but golf. They also have unlimited money for lessons and equipment. And most of these athletes have superior control over their minds and bodies and can adapt to other sports more quickly than us working folk ever could.
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If you ever want to make it on the PGA or Champions Tour Mark McGwire you're looking in the right direction for help.