on a roll

イチローが絶好調です。昨夜のアスレチックス戦では、イチローが打ったピッチャーゴロが投手のユニフォームの中に入り、「投手安打」（？）になってしまうほどです。スポーツ専門チャンネルESPNが絶好調ぶりを伝えています。

ICHIRO STAYS HOT: How do you know when you're on a roll? When you reach base the way Ichiro Suzuki did on Friday night.

Suzuki's bouncer back to the mound got lost in A's hurler Jarrod Parker's jersey. Parker couldn't pull the ball out of his jersey and Suzuki ended up with a single. It was Suzuki's 10th hit in his last 13 at-bats.

"I don't think they're will ever be a play like that (again). Ever," Suzuki said with a smile.

Suzuki also had a hit in the sixth but was thrown out trying to stretch it into a double. Overall, he has 11 hits in his last 15 at-bats. He also stole a base on Friday, giving him five steals in the last four games.

http://espn.go.com/blog/new-york/yankees

on a rollはイディオムで「好調で、うまくいって」という意味です。それはツキも呼び込むようです（"having a streak of good luck or good progress or success"）。見出しのstay hotも同じ意味です。
イチローは「死のロード」と称される休みなしの連戦ですが、それでもはじめての地区優勝へと、ノリにノっているようです。（GP）