SANDWICH, England, July 14 (Reuters) - Dustin Johnson has good memories of Royal St George"s after finishing tied second at the 2011 British Open and the world number one is confident of going one better this year. The 37-year-old American won the Masters in November, his second major title, and believes he is playing well enough to make a strong challenge for the Claret Jug this week. "Obviously, it"s the same golf course, but it was a little bit firmer in 2011," Johnson told reporters on Wednesday. "They"ve had a lot of rain, so it"s playing a little bit softer. But it"s starting to firm up a little bit, and I feel like the course in really good shape. The rough is definitely a little bit thicker than it was back then." Johnson finished three shots behind Northern Ireland"s Darren Clarke at Sandwich in 2011. "That was a long time ago, but obviously I have good memories here, and I did play well," he said. "I do like this golf course. I feel like it"s a tough golf course. It"s going to play difficult, especially with the wind direction that it"s supposed to blow for the week." Johnson described Royal St George"s as a typical links course. "You"ve got to hit golf shots, and you"ve got to hit them where you"re looking or you"re going to have a tough time," he said. "For me, I feel like most of it"s going to be driving. If I can drive it well, then I feel like I"m going to have a really good week." Johnson hit a rich vein of form last year, culminating in his Masters triumph at Augusta. "I played really well for about six, seven months. I feel like the game is starting to get back to where it was, just seeing a lot more consistency with the shots and the shapes," he said. "I think that"s probably just a little bit of the difference." Johnson accepts, however, that luck will play a big part in the tournament. "A bounce here or there can definitely be the difference between winning a major or not," he said. "Around links golf courses or at the Open Championship that can definitely come into play a little bit more, but everybody is playing the same golf course, and it"s all the same humps and bumps for everybody."