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Wednesday, December 16, 2009

Canada Olympic Trials: AKA Roar of the Rings

It was an enjoyable week for fans in Edmonton, but not necessarily for 14 of the teams participating. Four years of hard work, practice, travel, and time away from family and jobs, all culminated into one intense week of curling. Ultimately only 8 remaining players (ok, 10 if you include the 5th man/woman) experienced the thrill of victory. The remaining squads are left to wonder what could have been.
Speaking of the 5th position, will the CCA approve of the current extra teammates? Will the teams keep them or toss them aside? Does it really matter? Not for me to ponder I’d prefer to look at specific games and some of the decisions made throughout the week.

1. Randy Ferbey vs. Glenn Howard
Ferbey was 9-7 against Howard going into this game and needed a win to ensure their game against Koe Thursday night would have play-off implications.

5th End: Russ Howard (commentating for TSN) questions Ferbey’s decision to come into the rings on David’s last shot. A valid point and Randy’s squad is fortunate to get away with only giving up a single.

Ferbey is Red

At this stage, Ferbey is up 4-2, Howard has last rock. If the freeze attempt by Nedohin is perfect, Howard is likely forced to one. He could attempt a difficult double raise but more likely may try a delicate draw to the edge of the button avoiding the corner guard on the in-turn. Most likely Howard gets one and Ferbey is up 4-3 with hammer and 5 ends to play. In this situation his Winning Percentage (WP) is 80%.

If Ferbey instead throws a guard, he could cut-off Howard’s in-turn draw and make it difficult for him to get two. Glenn would have to play an out turn and try to catch half of the four foot. If we assume Glen makes his deuce 100% of the time, game is tied and Ferbey’s WP = 61%. If Glen gets three or four, which was possible given where David’s rock ended up, Howard’s WP is either 60% or 75%. Ultimately Ferbey is trying to gain Dominant position (80% or greater) rather than stay in a close game (<66%) at the risk of putting Howard in Control (>66%<80%).

I’ll spare everyone the formula (let me know if you’re interested), but Dave needs to make this corner freeze roughly ½ the time for the call to be correct.

9th End: Alan Cameron may have misquoted me slightly in his article: ( What perhaps I meant to say was “if you agree with Randy’s assessment of David’s chance to make that shot (4 or 5 out of 10) then it is the correct call”. Alternately, if you agree with Russ Howard’s assessment of Dave’s chances as 10%, then it is not. How often does he need to make the shot to make it the correct call?

If Ferbey takes one, WP = 25%. Taking stats exclusively from Grand Slam events show this number is closer to 20%. This is the only significant difference in numbers we see from Grand Slams versus all events. We’ll use 25% for now.

.25 = .6x +.12y +.01z +.25s

x = estimate the double is made for two
y = estimate Howard steals 1
z = estimate Howard steals 2
s = Ferbey takes 1

And x + y + z + s = 1

Let’s chose z as 10% and s as 5%.

.25 = .6x + .12(1-x-.001-.0125) + .01(.1) +.25(.05)

Solving for x = .246 or approx 25%.

If we assume s is 0 and z is 20% it only increases to 27%. Giving up a single or a steal of two to Howard has minimal difference in the probable outcome.

If we also think our chances of stealing in the 10th end is less than 25%, we are even more inclined to try the double. If we think we will only steal 20% (similar to Grand Slam numbers) then x = 14% or 16%. This is still above Russ Howard’s estimate, but well within range of Randy’s.

2. Kevin Koe vs. Glenn Howard
In the 9th End, Koe, trailing 5-4, is faced with a similar decision as Ferbey was in the previous example. Rather than draw for his single, Koe elects to play a soft out-turn take-out around the guard in front of the rings. It’s an attempt to score two but a miss results in a steal. No steal of two here, and perhaps some small chance his draw for one would be missed (needed full four foot). The hit he played could also possibly result in a single, but very difficult given that they were pushing shot stone towards the button. I’ll leave the calculations up to the reader, but appears their chances for two needed to be close to Nedohin’s in order for it to be the correct call.

Koe is Red
3. Koe vs. Gunnlaugson
Easily the most entertaining 7-2 game I’ve seen in a long time.

3rd End: Koe is up 1 without hammer. There is a single tight corner guard way out on the wing. Koe attempts a draw around on his first rock and comes light, leaving two stones staggered. Jason decides “because it’s the 3rd end” to draw to the open. The end is blanked. This is simply a case of over thinking a philosophy which I’ve heard before about “scoring in the even ends”. I even discussed some of this in my article from February 2009. In it, I discuss the 5th and 8th ends. Notice the 5th end is an odd numbered end; however in that article I argued preference to have the hammer.

Gunnlaugson is Red

A score here by Jason and a Koe score in the 4th gives Gunner hammer back in the 5th. An example: If Jason scores 2 here and then forces Koe to one in the 4th he is tied with hammer entering the middle game (5th end) and has 61% WP (Close Game). If Jason scores two in the 5th, his WP = 75%. If he waits to the 4th and holds Koe in the 5th, his WP = 62%. If he then scores two in the 6th, his WP increases to 79%. Interestingly enough, this is a .04 difference and shows Gunnlaugson does gain if scoring a deuce in the 4th instead of the 3rd. However, both are still in what I define as Control and not a Dominant position. And the overriding factor is, there are too many “IFs”.

All we specifically know at this stage is the chances at the end of the 3rd end: Blank WP = 43%

Jason scores two WP = 61%
Gunnlaugson takes one WP = 39%
Koe steals, Jason’s WP = 26%

In order for the call for two to be correct:

WP = .61x + .39y + .26z

x is a deuce for Jason
y is a single for Jason
z is a steal for Koe

We can likely assume the chance Koe steals is very small. Jason would only need to bite the eight foot to take one. Let’s assume z=0

WP = .43 = .61x +.39(1-x)

Solving for x = 18%.

Bringing a possible steal into play, we could estimate Jason needs to make his deuce more than 20% of the time to make the attempt at a deuce correct.

These WPs are also based on average numbers and I’ve stated before that the more ends remaining, the greater disparity from the average for teams of unequal strength we can expect. We can assume that Koe is a stronger team; however we can still compare the values and determine which decision leads to a better outcome.

The only possible argument to be made is that with fewer ends remaining, the result will be closer – but it is only one end less so it is not significant enough to sway our decision. For example, if you are a weaker team and win the toss, my theory would indicate your best chance may be to blank 9 ends and then be tied with hammer in the final end. This eliminates the chance your opponent will can use their superior skill during the many ends available to score multiple points. With free-guard zone however, this is simply not possible. At any stage your opponent can force you into a non-blanked end.

5th End: I’d nominate the 5th end in this game with the 9th end in Howard vs. Middaugh for “Best Ends” of the week. See image which shows the rock placement before Jason’s first stone.

Gunnlaugson is Red

There were multiple calls which could be argued several ways and all opinions could likely be supported. One thought I’d like to bring up was Jason’s comments heard on CurlTV of a “big end” vs a deuce. Should they position for a “big end” or try for the deuce?

At this stage, Gunnlaugson is two down with hammer. Here are various WPs at end of the 5th, based on possible outcomes from this end:

Koe steals, Jason’s WP = 11%
Single WP=20%
Deuce WP = 39%
Three WP = 61%
Four WP = 75%

I won’t even begin to analyze the possibilities based on rock position, etc. Have fun if you like. In general, I like Gunnlaugson playing for a big end based on the fact that he expects his opponent is stronger and the positioning of the rocks are such you may be able to take some risk and put the game back to Close or with a 4, take Control. If I’m the stronger team I would be more inclined to take my deuce and use my skill to create opportunities in the last half of the game. Unfortunately, Jason wasn’t able to make the big shot or place the rocks correctly to get the big end. Hats off to Kevin Koe who made a brilliant shot on his last to take away most of Gunnlaugson’s options.

4. Kevin Koe vs Kevin Martin
Martin is up 6-5 with hammer in the 9th End. On John Morris last rock Kevin Martin elects to keep the centre guard and play into the rings (see image). Why doesn’t Martin peel the guard here? If Kevin takes one or blanks, he leaves Koe with an 11-12% chance to win. If Koe steals it goes up to 20-25%. If Koe steals 2, as unlikely as it would appear, Koe now wins 60%.

Koe is Red

Kevin’s thinking could be:
“If I peel twice, Koe will hit on his last rock. I’ll face three and have to play a double and likely give up a   steal. If I play into the rings now, I at least give myself some chance to score and it is doubtful Koe could steal 2, which is my primary risk”.

During the CurlTV broadcast I questioned the call, preferring to peel. In retrospect, you can make a good argument for both decisions.

5. Glenn Howard vs. Wayne Middaugh
Wayne had a tough week. His first three games were Ferbey, Howard then Martin. He needed to come out of those three with at least a win but never got any momentum. The Howard game was a close one which could have gone the other way.

9th End: The 9th end was (along with Gunnlaugson vs. Koe 5th end) my vote for most exciting end of the event. It lasts nearly 25 minutes!

Check it out at  and link to Video.

The view of the house before Wayne throws his last rock...

Howard is Red

Howard is up 5-4 with hammer and elects to leave the long guard. This gets them into some trouble and they nearly give up a steal of two. See analysis above in Koe vs. Martin and think if a similar decision comes into play for Glenn at some point in the end.

6. Glenn Howard vs. Kevin Martin, Round Robin
Clearly the best game of the week. Unfortunate the final didn’t live up to the re-match we’d have wanted.

8th End: Martin is tied 5-5 without hammer and elects to play his first rock in the rings rather than play a centre guard. I wrote about this in several previous articles, including January 2009. Kevin is still the only top skip I’ve seen make this play.

Howard is Red
Martin’s final shot in this end was the shot of the week. Facing a 2 or possible three by Howard, Kevin makes a fantastic hit and roll, corner freezing to his own stone. Howard still has a raise for a multiple score but it is much more difficult and he is held to one instead of the game being possibly over. Because it’s tied in the 8th end, Kevin knows that whether Howard scores a two or a three it has little bearing on the outcome, they will likely lose the game.

What is interesting in this scenario is both the ability to visualize the shot and the dynamic between John and Kevin. At first Kevin didn’t like the out-turn. John was able to maneuver the conversation and ease Kevin into the decision, without challenging him. It is generally accepted that you don’t want your skip playing a shot he or she is not comfortable playing. This discussion captured parts of the game that are critical to success and can’t be simply analyzed by numbers.

Further to this, I’d suggest Curling is made up of 4 key areas:
1. Physical Skills
  a. Throwing the rock
  b. Sweeping
2. Mental Skills
  a. Reading ice and rocks
  b. Communication
     i. Calling line
     ii. Judging weight
3. Strategy
  a. Calling the game
4. Psychology
  a. Emotional control
  b. Team chemistry

My blog focuses almost exclusively on Item 3. This is an example of item 4. In these cases, teammates become like a caddy who is discussing which club to play on an important shot. It’s not always about which club is correct but about how the caddy interacts and builds confidence in the golfer. These areas are ranked by what I would consider level of importance, although top teams are generally strong in all areas.

If you’d like to review video from any of these games or others, check out or and click on Video.

Have a Safe and Happy Holidays!

1 comment:

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