In 1989, Michael Lewis won acclaim for his bestselling Wall Street expose, Liar's Poker. In the book, he described, in unflattering detail, the Wall Street excesses he witnessed as  a bond salesman for Salomon Brothers, now part of Citigroup (NYSE: C). When Lewis exited that madness in the 1980s, he thought he'd observed the end of an era. He was wrong.

"Liar's Poker ends up being the beginning, instead of the end," he said on a recent visit to Fool HQ. "What I wrote is an antique document of a relatively innocent age, when Wall Street spun out of control in the exact same direction it was going in when I was there in 1988. It just kept going for another two decades."

Party like it's 1989
Lewis is currently addressing that unfinished business: He's writing a new book, due out later this year, that will pick up on some of the themes he last wrote about in the late 1980s. But he stopped by our Alexandria, Va., offices as part of a tour for his new book, Home Game: An Accidental Guide to Fatherhood.

Lewis chatted with us about baseball, being a dad, and a few other things under the finance sun. Here are three quick hits from Lewis' talk:

1. Moneyball and the financial crisis
When Lewis' popular book Moneyball first came out, he said Wall Street seized on it immediately, allegedly applying the book's principles to its own practices in order to better measure value and risk.

"The general idea that there are better ways to measure value is applicable to all kinds of things, but you've got to be very careful how you apply it," Lewis said.

However, Lewis thinks people liked the idea more than the fact of it. As he put it, "total catastrophe" ensued on Wall Street. "The central lessons of Moneyball were largely ignored by the people paying the closest attention to it," he said. "One of the central lessons is: Be careful what you measure, because you could measure the wrong thing, and it could totally screw you up."

Anyone can pull up a 2008 stock chart of major banks like Bank of America (NYSE: BAC), Citigroup, Goldman Sachs (NYSE: GS), and Morgan Stanley (NYSE: MS) to see that Lewis is onto something. Continued...