This is a common question that is asked during my lesson time; How far should I hit my 7 iron
The 7 iron is a pretty standard benchmark number which golfers tend to compare themselves against (the other obviously being the driver distance). So, with that in mind, my research discovered a few interesting test results that were carried out using Trackman to measure.
Several golf balls were struck aiming to swing at the following common 7 iron swing speeds
65 mph (typical slower amateur)
75 mph (average amateur)
85 mph (quicker amateur)
Also only included results which had a higher smash factor than 1.36, indicating a pretty decent strike quality (especially for amateurs). I also only included swings which were within 1mph of the desired swing speed. 8 balls were Included in each category of shot – the results show the averages. Also only shots that which finished within 10 yards of the target line were included, which is straighter than the average tour proximity to the pin.
First, let’s have a look at the birds eye view of the results.
All of the shots were pretty straight, as they are only ones which were included which fit the criteria. If we have a look at the numbers for these below, we see in more detail what happened.
Although these were averages, they actually rounded up nicely to the desired swing speed. The results show carry distance (distance in the air). I didn’t include total distance, because this will be influenced by green hardness. But, you should be more concerned with carry distance, as that is what you are trying to optimise when flying the ball to the pin and over bunkers etc. The smash factors were all the same (slight advantage for the slower swing speed) showing equivalent strikes. What the data shows is that
Spin rate increases as swing speed increases
Carry distance increases with about 25 yards for every 10mph
The ball flies on a much higher trajectory when swing speed increases, even though the launch angles were within 1 degree of each other
I think that last point is important to understand. As speed decreases, the ball flies much lower. Many slower-speed amateurs I see are trying to launch the ball as high as their faster swinging golf partners. As a result, they artificially manufacture this height by using poorer technique (such as hanging back and scooping). I think that, if players with less speed realised the height they should be hitting for their current speed, they would be more inclined to make the technical moves they desire (such as weight being on the left side more, and hands leading the club head into impact. How a player is visualising their ball flight will have an impact on the technique they use
So, the answer to the question “How far should I hit my 7 iron” is that it depends. For a start, the distance you hit the ball is ultimately limited by the speed you produce (you are not going to hit the 7 iron 170 yards with 65 mph speed). But things such as strike quality are also huge. Strike will determine whether you achieve your potential distance.
For this article, my research was based on using strikes which were over 1.36 smash only, and averaged at 1.38. This is a very high quality strike – your average shots are unlikely to be this high – so the carry values presented here are likely to be your optimal distances with a given swing speed, and not the average (although better players may actually have a high average smash factor).