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Sunday, September 19, 2021

Ryder Cup Musings: Na VS Rahm

Thursday I did a post giving some of the reasons I believe Team USA struggles so at the Ryder Cup. Today I'm staging a big grudge match between Kevin Na and Jon Rahm to test some of those reasons.

This is a long post, folks, so grab a drink and some popcorn and settle back for a while.

Kevin Na and Jon Rahm

The primary reason Steve Stricker gave for not choosing Na was lack of distance... and Kevin issued his own statement that basically said Team USA needed better putting more than extra distance. I agree with Kevin and have expressed this idea many times, from my Solheim Cup post last week to a huge post in September 2014 where I recalculated EVERY SINGLE MATCH TWICE to demonstrate where the points were lost.

But the fact remains that statistics say distance is the key. We hear that drummed into our heads in the coverage of every tournament, don't we? The problem is that statistics lie and I hope to show you that in this post.

I know you'll protest. "Mike, numbers don't lie!" And I agree with you. But the problem is that numbers mean nothing until they're interpreted... and interpretations lie all the time.

Statistics are just interpretations of the numbers. They are an effort to make sense of them, but they can say different things depending on what you're looking at. You need to pick stats that accurately address the issues you're interested in.

My argument in the first of these posts is that we're using stats that DON'T address those issues. In this case, we're using stats that interpret four-round individual stroke play competitions to choose players for single-round match play that involves both single and dual player teams. And as it stands, we can't get direct information on these specific points.

But I believe we have been presented with a unique situation here where we can at least create some stats that are more suited to answering the questions we have. Best of all, we can create these stats using information comparing Na's performance to the #1 player in the world, Jon Rahm!

I'm using the FedExCup Playoffs as the basis for my calculations. Both men played all three consecutive events and spent the first two weeks trying to get as high in the rankings as possible, then trying to win the $15mil the last week. While this isn't exactly match play -- the two weren't trying to beat each other one-on-one -- it's probably as close as we're going to get.

What did the Ryder Cup points list see and use to award Kevin's points? It's very simple:

  • Jon Rahm finished 3/T9/2* for the Playoffs
  • Kevin Na finished T8/T17/3* for the Playoffs

The reason for the asterisks is that, had we not used the staggered start at the TOUR Championship, Na and Rahm would have had the same aggregate score and would have played off for the FedExCup. Based on these stats, Rahm clearly played better than Na... and we all know that, under normal conditions, Rahm is much longer than Na.

But those are 72-hole scores. What happened round-by-round, which is how we determine winners at the Ryder Cup?

I decided to find out... and as you can see, I did so many calculations that my scanner couldn't get all of my writing in these photos.

Two pages of calculations

I'm not going to try and tell you all the things I discovered during this stat gathering project. But what I found makes me question Team USA's criteria for choosing their players.

First, let me make one thing clear: I am NOT saying that my project proves Na should have been chosen for the team. All I'm saying is that the stats currently being used don't give us any real indication of what might happen in match play. Likewise, both Kevin and Jon have great match play records and they might make some different choices if they were actually going head-to-head. But I think this is as close to match play results as we can get from the regular Tour stats.

That said, let's get on with it.

Since match play is built on single 18-hole (more or less) rounds, I broke these three Playoff events into 12 "matches" and compared the scores. We'll start with the stroke play scores:

  • Kevin Na:
    67-66-70-68 || 72-65-69-67-|| 66-67-66-67
  • Jon Rahm:
    63-67-67-69 || 64-66-70-70-|| 65-65-68-68

Just from these numbers we can see some interesting trends:

  • Rahm has the lowest score in the first match of each tournament.
  • Na has the lowest score in two of the second matches of each tournament, Rahm one.

That means that Rahm takes Na 4-2 in the first six matches. But let's keep going:

  • Na wins two of the third matches of each tournament, Rahm one.
  • Na wins all three of the final matches of each tournament.

These are stroke play scores, not match play, but would you have expected Na to win 5 of the 6 weekend matches and all three on the last day? Sounds like Na is quite the closer!

Overall, Na beats Rahm 7-5. Unexpected, to say the least.

Now, if we go through and recalculate all the matches, using the stroke play scores to figure out who would win each hole if this was match play, we see basically the same thing. There are some slight changes simply because -- as I said in the first post -- not all strokes count in match play. Here's a quick example of how it works:

Say Player1 wins the first hole with a birdie and Player2 makes double-bogey. Player2 wins the second hole with a birdie and Player1 makes par. In stroke play Player1 has a one-stroke lead but in match play the two men are even. It doesn't matter how many strokes you win a hole by in match play, you're still just 1up.

Here's how the twelve matches play out:

  1. Rahm wins 4up.
  2. Na wins 1up.
  3. Rahm wins 2up. (He won by 3 in stroke play.)
  4. Na wins 2up. (He actually won by 1 in stroke play.)
  5. Rahm wins 6up. (He won by 8 in stroke play.)
  6. Na wins 2up. (Again, only a 1 stroke win in stroke play.)
  7. Match is halved. (Na actually won by 1 in stroke play.)
  8. Na wins 3up.
  9. Rahm wins 2up. (Only 1 stroke in stroke play.)
  10. Rahm wins 2up.
  11. Na wins 2up.
  12. Na wins 1up.

Overall, Na beats Rahm 6.5-5.5. One of Na's stroke play wins became a half in match play, but Na still comes out on top.

There is, of course, one more question to answer. How long are the Playoff courses where Na won? After all, we know Rahm is noticeably longer than Na and this would be a concern at a long course like Whistling Straits.

Or would it? Here are the lengths of the Playoff courses, taken from the PGA Tour tournament sites:

  • Northern Trust
    Liberty National GC, 7410yds/par-71
  • BMW Championship
    Caves Valley GC, 7542yds/par-72
  • TOUR Championship
    East Lake GC, 7346yds/par-70

Whistling Straits will play 7390yds/par-71.

There are a lot of things that contribute to how long a course plays, like the size, contours and grass on the greens; the bunkering, both in the fairways and around the greens; how narrow the fairways are; how high the rough is; how hilly the course is; and so on. I have no idea how I could possibly compare all those variables... but I do know how to compare the overall length, so that's what I'll do.

Here's my formula: Take the course's par, subtract 36 (that's two putts for each of 18 holes) -- that gives me the number of shots you expect to hit between tee and green. Then divide the course length by that number of shots. I can use that "average yards per shot" to compare the length.

  • Liberty National: 7410/35= 211.7 yards
  • Caves Valley: 7542/36= 209.5 yards
  • East Lake: 7346/34= 216.1 yards
  • Whistling Straits: 7390/35= 211.1 yards

Hmmmm. It would appear that Whistling Straits is the second SHORTEST of the four! The longest, East Lake, is where poor shortknocker Kevin Na matched the low score of the much longer Jon Rahm. In fact, Na performed his best on the longest course. Hmmmm...

I've proven my point. While this post doesn't prove that Team USA should have picked Kevin Na, I think I have proven that, on a round-by-round basis -- which is how match play is done, after all -- Kevin Na doesn't seem to be at any real disadvantage on a long course against a long hitter when both are playing well, and that perhaps Team USA needs to reevaluate the stats it uses to choose its team.

And that leads into my final post. Look for it sometime next week.

3 comments:

  1. Hyo Joo Kim came out of her post Olympic break with a win on the KLPGA this week at the OK Savings Bank Se Ri Pak Invitational.
    The guys of the KPGA meanwhile contested the DGB Financial Group Irvine Open, with Sang Hyun Park emerging victorious.
    Zimbabwe's Scott Vincent won the ANA Open Golf Tournament on the JGTO.
    The JLPGA was forced to shorten the Sumitomo Life Vitality Ladies Tokai Classic to 36 holes due to weather, with Yuna Nishimura coming out on top.

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  2. I also agree with Na. That Team USA needed better putting more than extra distance. Although that is only one of Na's overall game strengths. I think Na has a great knack at exercising match momentum. Picking Na, would have given Team USA a more rounded team, the better to set up matches with. I watched the final round of the championship when Na was playing with and against Rahm. I was impressed with Na's play. I would say Rahm, is happy with Stricker's choice. Striker might have been wise to capitalize on that particular match synergy.

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    Replies
    1. And since it appears they're going to play Whistling Straits a bit shorter, with more drivable holes, I can't see how giving Na more wedges into the greens would hurt his scoring ability.

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