Wrong Ball

I did that in a 36 hole scratch final a few years , the ball spotters told me that was my ball so i played it and holed out only for a player in a group ahead playing the other way to come back and advised me he played my ball , I checked it and so it was , lost of hole , never made that mistake again , same ball and number but one black dot and I mark mine with 2 , ....................EYG
 
It happened to me today. It was a lads 40th birthday and 16 of us went to play a local course. We had a better ball comp and my tee shot on the first went into the water. I pulled another ball out, identified it as a Callaway 3 and played my shot but could not see exactly where it finished due to where I was standing.

One of our opponents had also gone in the water about 10 yards in front of me and he also dropped and played. We walked towards our balls and he played a ball on the fairway leaving another ball in the light rough. That ball was a Callaway 3 but did not have any of my markings on. Despite me saying I didn't think it was my ball the others said it must be as that was where it went.

As my partner was already on the green and I would not be on the scorecard I played the ball anyway. Our opposition then completed the hole but neither of them scored. One of them then came over to me and asked me if the ball he had was mine, which it was. He had played 4 shots with my ball and not noticed.

As an aside our opponents went on to win the comp with 46 points, despite their blob on the first.
 
From the US Open site.

VILLAGE OF PINEHURST, N.C. – Each of the 89 players who missed the cut at the 114th U.S. Open on Friday has a story of personal disappointment to tell. In the case of Hunter Mahan, his story includes caddie John Wood.

“It was 100 percent on me,” said Wood of a two-stroke penalty that was assessed to Mahan for hitting fellow competitor Jamie Donaldson’s ball on their ninth hole in Friday’s second round at Pinehurst Resort & Country Club’s Course No. 2. As a result, Mahan finished with a second-round 72 and a 146 score for the championship, one stroke shy of the 5-over-par 145 cut line.

On the 455-yard, par-4 18th hole, Wood was the first person in the group to reach the tee shot sitting in the left-center of the fairway. Wood noticed a slash, similar to one Mahan makes, across the ball’s number and assumed it was Mahan’s ball. Not until the players marked their balls on the green did Donaldson notice that he and Mahan played the other player’s ball from the fairway, a violation of Rule 15-3b (Wrong Ball-Stroke Play).

Mahan and Donaldson replayed their approach shots and both went on to record double-bogey 6. Both players were assessed a two-stroke penalty. Donaldson finished with an 81 and also missed the cut at 11-over 151.

“Off the tee, it looked like Hunter's [ball] was in the left-center and Jamie's was on the left edge,” Wood said. “And we got up there and they were switched and we didn't realize it. You are out here every day for 17 years, you know where the ball goes in the fairway. I can't grasp where the ball ended up. That was no excuse, it was my fault.”

Mahan described Wood’s mistake as a fluke.

“I've played a lot of rounds of golf now and it's happened maybe one time before,” he said. “Off the tee, it looked like that's where my ball should have been, and I couldn't explain to you how it ended up where it did. Just got to pay more attention.”

Mahan’s explanation did little to lessen Wood’s guilt, especially since it ended up costing Mahan, the 1999 U.S. Junior Amateur champion and 2002 U.S. Amateur runner-up, a chance of playing on the weekend.

“Yeah, that's the worst of it,” Wood said. “And he played so good today. The two-shot penalty probably cost him three, because he had a really great look on the [initial] shot he hit in there for birdie.”
 
Did it yesterday in monthly medal :( Was even talking about last time I did it before I went out. I'll never say 'I'll never do that again' as that's what I said last time. Ah well. Must just take more care in future.
 
Top