This is from what may be the most memorable Ryder Cup of all time.  Payne Stewart, Phil Mickelson, Justin Leonard, and others propelled the U.S. to victory.  Unfortunately, the flags that were produced for the tournament did not come with any copyright tags on the back.  With this being a screen printed flag without tags from a popular tournament, you can imagine the amount of counterfeiting.  Your best bet is to compare yours to one that you know is authentic.  The authentic flag measures 13 3/4" x 20".

Unsigned Value: $60-$80

  2001/2002 Ryder Cup Flag

Undated Yellow flag. 

Unsigned Value: $40-$60

  2004 Ryder Cup

Unsigned Value:  $40-$60