The Kansas City Royals are hot again. They've won nine of their past 12 games, they're 19-7 since Aug. 6 and just scored 27 runs their past two games. They're on pace for 100 wins, giving them a chance to challenge the franchise record for wins of 102 set in 1977. That team had one of the great runs in baseball history, going 35-4 from Aug. 16 through Sept. 25, including a 24-1 stretch.

Those Royals were one of the best success stories of the expansion era. Born in 1969, they finished over .500 in their third season and finally broke through to win their first division title in 1976. Under general managers Cedric Tallis and then Joe Burke, the team was a combination of astute trades -- Amos Otis, Freddie Patek, Hal McRae, John Mayberry, Darrell Porter -- and homegrown players such as George Brett, Frank White, Dennis Leonard, Al Cowens, Willie Wilson and Paul Splittorff.

The 2015 Royals are likewise a mixture of homegrown talent and acquisitions via trade or free agency. Rany Jazayerli, longtime Royals fan and blogger and now Grantland contributor, outlined how general manager Dayton Moore built this team and why it has been better than most predicted in the preseason:

"The Royals hold the best record in the American League because basically every warning sign for why they should decline turned out to be a false alarm."

Concerned their defense would regress? Per FanGraphs, the 2013 and ’14 Royals were 88 and 75 runs above average defensively, respectively, the second- and fifth-best marks in a database that goes back to 2002. With a month left in the season, the 2015 Royals are already at plus-61 runs on defense, nearly three times as good as the second-place AL team (Tampa Bay, at plus-22). Since advanced defensive metrics were first invented around the turn of the millennium, no team has put together a defense as consistently great as the 2013-15 Royals.

Concerned their bullpen would regress? While Greg Holland has a 3.83 ERA after battling a cranky arm all season, Wade Davis and Kelvin Herrera have been just as effective as last year, and the pen has gotten an added boost from Ryan Madson (2.45 ERA) and Franklin Morales (2.13 ERA). Luke Hochevar, still working his way back to full strength following Tommy John surgery, has a 3.29 ERA. Brandon Finnegan had a 2.96 ERA before he headlined the Cueto trade. The Royals' bullpen is so deep that the team had to release Jason Frasor because of a roster crunch while Frasor was carrying a 1.54 ERA.

Their excellent bullpen factors heavily into their success in close games, which is why for the second straight year the Royals’ record is substantially better than their run differential would suggest. They’ve outscored their opponents by 95 runs, a good sum, but one that pales in comparison to the Blue Jays’ plus-197. The Royals have exceeded their Pythagorean record by a full four wins.

Jazayerli points out that Moore took a long time to clean up the mess he inherited: "As late as 2012, the Royals still hadn't won more than 75 games in a season under Moore. Six years was enough time for the Washington Nationals to collapse [from 73-89 in 2007 to 59-103 in 2009] and rebuild [98-64 in 2012], while the Royals were going nowhere fast. Though the farm system was slowly turning into a juggernaut, Moore was doing things at the major league level that defied understanding."

As I wrote a couple of weeks ago, there has been some good fortune in the Royals' rise to success, such as Alex Gordon bombing out at third base and returning to the majors as a Gold Glove left fielder. Jazayerli addresses all of that and the complicated relationship Royals fans have had with their GM.

All I know is this: If the Royals win the World Series, 2006-12 will look like a long time ago.