They lead the Stormers by two points and are ahead of their nearest New Zealand rivals, the Highlanders, by five, and go into tomorrow night's match against the Hurricanes as short $1.45 favourites at the TAB.
Clarke, who will captain the side in his 50th appearance for the franchise tomorrow night, said there was a belief in the Chiefs side that had been missing in previous campaigns.
And he thinks the team, with talent such as Sonny Bill Williams, Richard Kahui, Tim Nanai Williams and Lelia Masaga, can only get better.
"The confidence levels are pretty good. Obviously with where we are on the table you sort of have to be confident with what you are doing," he said.
"But there's still a hell of a lot of improvement for us to do. We are sort of winning a few games with our guts and determination in our [defence] and making it quite hard so our attacking execution has to be better."
Young prop Josh Hohneck said the Chiefs had a clear plan when the team assembled at the start of the year.
"Our goal then was to win our first Super Rugby title so we started with a clean slate and every game is a different game," he said.
"But we have done all we can to get the crowds along and we just want to play well so everyone can have a good night."
Nearly 12,000 tickets had been sold by yesterday for the match.
This is well ahead of the average 8000 tickets that were sold for Chiefs home games last year but the side is hoping for a crowd of at least 15,000.
Chiefs media manager Kylie Sousa is expecting further ticket sales today and a good walk-up crowd before the match.