Jordan Spieth described his first round at The Open at Royal Birkdale as a 'nine out of ten' effort as he shot five under par.

The world number three is in a three-way tie at the top of the leaderboard with fellow Americans Brooks Koepka, the US Open champion, and Matt Kuchar, but there are plenty of players under par and Spieth, a two-time major winner, knows there is a long way to go yet.

The 23-year-old will tee off on Friday afternoon and he is set to get the worst of the weather, which is expected to be windy and wet on the second day.

"Given the forecast coming in, I thought you really needed to be in the red," he told reporters.

"Everything was strong. I give it a nine across the board for everything - tee balls, ball-striking, short game and putting. So things are in check. It's just about keeping it consistent.

"I'd call it a top five major round that I've played."