Despite 22 European Tour titles, the 38 year old has never won the flagship event.
In fact, the Englishman's tenth-place finish last season was his best since he was runner-up to Colin Montgomerie 11 years ago.
"Sometimes you just can't explain it," he said. "Why play it well in October in the World Match Play and make umpteen birdies, and then here in May and your best finish is second?
"I played well, but just not put four good rounds together in the last few years. One round has let me down here or there. I don't know what I finished last year I don't think I was too far off the winning score. I think I was about level or one under and six under one, so five shots over four rounds is not far off.
"I haven't had that blitz during a round where I've made five birdies in seven holes or something like that to really get some momentum going."
However, the World Number One is not going to get too hung-up on the reasons for his lack of success at the home of The European Tour.
"There's a few during the year," he added. "Doral - I always play that golf course - and I think I love this golf course, this is really going to suit me and the best I've done is 18th. There's a few.
"Sometimes you just can't explain it. There's no reason for it, just one of those things. I suppose that's why golf is great - sometimes you just can't put your finger on it."
Westwood finds himself under pressure for top spot in the Official World Golf Ranking from Luke Donald and Martin Kaymer once again, but following back-to-back wins in Asia and an impressive display at last week's Volvo World Match Play Championship - he was narrowly edged out by eventual winner Ian Poulter in the last eight - the twice European Number One insists his confidence is sky-high.
"I played okay the first couple of months of the year," he added. "But not really found much form on the greens, and historically I've not been too fast a starter in years gone by, so that didn't worry me too much.
"It was nice to get a couple of wins back-to-back, and start seeing a few 20 footers go in, and then played well again last week.
"This is obviously our showpiece event of the year. It attracts one of the best fields around a good golf course."