Biddle, 21, moved up one spot from the No. 2 overall ranking a year ago. He had been behind righthander Trevor May, whom the Phillies traded to Minnesota as part of the deal that brought them centerfielder Ben Revere on Dec. 6.
Even if May had remained in the organization, Biddle would have likely jumped to the top spot based on how well he pitched at single-A Clearwater last season. He is expected to pitch for the double-A Reading Fightin Phils in 2013.
"Wherever I pitch next year, the ranking and whatever Baseball America says, it doesn't matter," Biddle said. "I just have to keep doing what I've been doing and keep working as hard as I have been. If anything, the ranking is motivation to prove that I can meet the expectations."
Biddle, a Germantown Friends School product from the Mount Airy section of the city, has a three-year professional record of 21-15 with a 3.21 ERA. He has allowed 273 hits, walked 140 and struck out 325 batters in 3191/3 innings. All of those numbers have been accomplished at minor-league levels where the players were typically older and more experienced. In his first two full minor-league seasons, Biddle also overcame slow starts, which is another positive sign for a young pitcher.
Biddle said he has never felt the pressure of being the first-round pick of his hometown team.
"What some people call pressure, I call familiarity," he said. "I feel fortunate to be able to have family and friends in the stands. It means a lot to me. Whatever happens during a game, I'm able to walk out of the clubhouse and have family and friends smiling and in my corner. That's such a good motivator for me.
"Whenever I go to Reading, I think I will definitely have some people there to cheer me on. Everybody has been telling me since I first signed that they will definitely be there when I get to Reading. Even people I don't necessarily know that well said they will be there for me and it's great to have that kind of support from your neighborhood.
"I've always said that being from Philadelphia, you always have a chip on your shoulder. You're hard-nosed and work hard. That's how I was raised and that's what this city has done for me."
Biddle has been working out at Balance in Chestnut Hill with longtime trainer Aaron Sistrunk and at the Salvation Army Kroc Center in Germantown in preparation for the start of spring training.
"I can't wait," he said.
The rest of Baseball America's top 10 Phillies prospects: 2. Roman Quinn, SS; 3. Tommy Joseph, C; 4. Jonathan Pettibone, RHP; 5. Adam Morgan, LHP; 6. Ethan Martin, RHP; 7. Cody Asche, 3B; 8. Maikel Franco, 3B; 9. Darin Ruf, LF/1B; 10. Carlos Tocci, OF.
Contact Bob Brookover at email@example.com or follow on Twitter @brookob.