Large lie adjustment

[torxx]

I am average in build, 5’9” tall, 175 lbs., and seemingly avg length arms, and have been working on my swing with a pro the past few years. 5 Handicap.

Here is my delima: I bought a used set of Irons (MP 68 with tour TT shafts) that are ½ longer than std shaft and  1 degree upright on the lie. I did not need the ½ longer shaft for my build, but did not think it was such a bad thing, as I could simply choke up a little on the grip which I like to do anyway. After hitting on a lie board to check the lie for my swing, I ended up having to adjust the irons to 4 degrees flat (could use another ½ to 1 degree flatter to get a perfect mark on the lie board). That was surprising to me and the club fitter? Would the longer shaft be part of the seeming large degree of flatness? I do not believe my swing is unusually flat as my pro would have advised me on that by now.…Any thoughts would be appreciated.

[MEfree]

The longer the club, the flatter you will tend to swing it, so yes, the +.5" could be partially responsible.

[geauxforbroke]

The lie angle is all about the relationship between the height of your hands and the length of the shaft at impact. Think of a right triangle (like the one below). "a" represents the height of your hands at impact (not at setup), "b" represents the distance from a point directly below your hands on the ground and the ball, and "c" represents the length of the shaft. Assuming "a" does not change, as "c" increases, "b" also increases and the small angle created between "b" and "c" gets smaller and the resulting lie angle gets flatter.

Notice above I mentioned that the lie angle is a result of your hand positioning at impact . How you set up the club is irrelevant. For example, I am 5'11" and hold my hands pretty low. I was fitted last year, and was told I need 2 degree upright irons with standard shafts. With irons in this configuration, the toe of the club is up at setup, but at impact, the sole of the club is flush to the ground. The relationships change totally at impact. My irons are 3/4" longer than standard, so the correct lie angle is "standard". For me 3/4" made 2 degrees difference. The lie board doesn't lie, pun intended.