I recently took a tenor banjo class at Augusta Irish Week taught by Pauline Conneely. She's a brilliant player and the sibling of the well-known fiddler and bouzouki player Mick Conneely of De Danann. I loved Pauline's fluid, non-technical, and relaxed style with an emphasis on rhythm. Her banjo playing is featured on the new CD by her band Chicago Reel.
The only thing we disagreed on was tenor banjo fingering. Pauline was adamant that mandolin fingering was the only way to do it. (Mandolin fingering is where you place your index finger on frets 1 and 2, middle finger on frets 3 and 4, ring finger on frets 5 and 6, and pinky on fret 7). However, I use what is called guitar style fingering or the four-fingered approach where you place one finger per fret: index finger fret 2, middle finger fret 3, ring finger fret 4 and pinky fret 5.
This guitar/one finger per fret assignment is used by such players as Angelina Carberry, Darren Maloney, Gerry O'Connor and Pio Ryan. It's how I was taught by old-time tenor banjo player Josh Bearman of The Hot Seats, and I'm pretty sure this is also how Irish style fiddler Cleek Schrey instructed me when I took a few tenor banjo lessons from him starting out. I find this fingering to be a more comfortable and natural way of playing tenor banjo. By contrast, a lot of big players do/did use the mandolin fingering that Pauline ascribes to, including Barney McKenna, Mick Moloney and Enda Scahill, to name a few. (I think people who play mandolin or fiddle first and then take up tenor banjo tend to use the mandolin fingering out of habit.)
If you can make the stretches, mandolin fingering does reduce hand movement since you mostly just move your fingers, arguably making it easier to reach the 7th fret. However, that appears to be its only benefit. For me mandolin fingering requires an unnecessary stretch to get the middle finger to the 4th fret and the ring finger to the 5th fret; and all that stretching can lead to fatigue in the fretting hand. It's easier and more economical to place the ring finger on the 4th fret and the pinky on the 5th fret so that you eliminate those initial stretches and keep your hand in the most productive position, especially considering that at least 80% of the tunes can be played without even having to go beyond the 5th fret. Another benefit is that when you frequently use all four fingers, your little finger - and entire hand - becomes more agile and strong.
The main thing I learned from Pauline's class - besides slowing down - is that when the tune does call for the 7th fret B you need to be able to play that smoothly without losing the flow of the tune. I have to shift from first position to second position to get to the 7th fret and I’m still struggling with making this move cleanly. So, I know what I need to practice!
Before I took the class I had no idea there was such debate over fingering. There will always be exceptions to the rule - certain odd phrases or tunes that dictate alternate fingerings than what you are used to - but I still believe one finger per fret to be superior in most cases.