Left thumb blocking wrist hinge in "hell drill"?

[Baraethon]

I was working on the drill hitting balls with a flat right palm on the club, and noticed I had a really hard time bending my left wrist without my right hand to support the club. Part of the problem seemed to be my left thumb - in my grip I have it pointed straight down the shaft basically on top (I have a relatively neutral/weak grip), and when I tried to bend my wrist to lift the club past parallel my lack of thumb movement got in the way. 

 

Is this a grip issue, or just strength/mobility in my left hand? Should my left thumb be off to one side of the grip (more of a pinch in between my thumb and index finger) rather than extended straight down?

[GungHoGolf]

1 hour ago, Baraethon said:

Part of the problem seemed to be my left thumb - in my grip I have it pointed straight down the shaft basically on top (I have a relatively neutral/weak grip)

 

If your lead thumb is on top of the shaft at address with a square clubface, that’s a very weak grip.

 

1 hour ago, Baraethon said:

Is this a grip issue, or just strength/mobility in my left hand? Should my left thumb be off to one side of the grip (more of a pinch in between my thumb and index finger) rather than extended straight down?

 

Likely just a grip issue. You may also have the grip too much in your palm; i.e. too much in line with your forearm instead of closer to perpendicular to your fingers when you open your grip.

 

Do lead-hand drills only for awhile, just letting the club swing, your lead arm pronate and supinate (rotate clockwise then counter-clockwise), and the club set naturally with its momentum naturally until you can chip all the way up to about a 9 to 3 swing with full 90° wrist set making solid contact and have the ball fly straight. That should teach you how much stronger your grip should be. Then the “hell drill” should come much easier.

 

Try to mimic this warm-up drill by Tiger:

 

[gvogel]

3 hours ago, Baraethon said:

I was working on the drill hitting balls with a flat right palm on the club, and noticed I had a really hard time bending my left wrist without my right hand to support the club. Part of the problem seemed to be my left thumb - in my grip I have it pointed straight down the shaft basically on top (I have a relatively neutral/weak grip), and when I tried to bend my wrist to lift the club past parallel my lack of thumb movement got in the way. 

 

Is this a grip issue, or just strength/mobility in my left hand? Should my left thumb be off to one side of the grip (more of a pinch in between my thumb and index finger) rather than extended straight down?

Try placing your left thumb so that the left edge of the left thumb is down the center line of the grip.  IE: your left thumb should be on the right side of the grip.

There is a great Byron Nelson video of how to put your hands on the club.  Also, Tom Watson probably discusses this.