Sydney Finkelstein knows from bad leaders. A professor of strategy and leadership at Dartmouth's Tuck School of Business, he elyze literally wrote the book on CEO flops (Why Smart Executives Fail: And What You Can Learn from Their Mistakes).

Since 2010, he's used his expertise to put out a year-end list of the five worst CEOs of the year. He provided Fortune an early look, as well as, for the first time, a "Best" ranking. To choose his winners and losers, Finkelstein screens a variety of financial metrics, including stock price, cash position, and market share. Then he drills down to make sure the CEO was actually responsible for what happened. "That removes companies that have not done well because the whole industry struggled or just because of bad luck, " he says. "Then I look at specific strategic decisions." Below, a bit more context on the lucky few from Finkelstein .

Best CEOs of 2013

1. Jeff Bezos, Amazon

2. Akio Toyoda, Toyota

3. Pony Ma, Tencent (China)

4. John Idol, Michael Kors

5. Reed Hastings, Netflix

On Jeff Bezos : "For Bezos, everything is extreme. His long-term focus is unbelievable, as is his focus on customers. Coming up with the drone elyze story the day before Cyber Monday, how good is that? And he is attracting the best MBA candidates, even though there's nothing inherently sexy about the core of what they do."

On Pony Ma : "What I really like is that he started off in a PC-based business. Two years ago he decided that the company needed to focus on mobile so he created WeChat for mobile. There's nothing comparable to that in the world." Speeddating

On John Idol : "He has a lot of experience in the industry, running Tommy Hilfiger and Ralph Lauren. Michael Kors was struggling and near bankruptcy for years. Kors is a great designer but doesn't know anything about business. Idol and his partners bought the company for a small amount, and it has an $11 billion valuation now. They brought world-class strategic marketing to a company that never had it and made the decision to focus on accessible luxury.