Ackerman's mathematically rational decision

If the Lions lose next week, Ackerman's decision to B team it against the Jags will get renewed unfavorable reviews....forcing the Lions to travel. But we should understand, there was only about a 50% chance the Canes would be there for the final....
.75 X .9 X .7 = 47%....the probabilities for the Hurricanes beating the Saders in the pool, the Sharks and the Chiefs. Call it 50%.
How does this effect things? Well a whole lot. So before Ackerman made his decision, he was looking at two paths to winning....one where he eschewed sending his best to Bargie, which includes two strands
.8 X .75 X .7.....x .5 = .21 for the Canes losing and one of the other NZ teams in SA. 
Plus
.8 X .75 X .2.....X .5 = .06 for the same path of NZ teams of ascending quality, but an away final against the Canes with only 20% chance of winning.

So the total probability of winning the cup following the path of not playing the key players against the Jags is 27%. 
And the other path which made a full hearted effort to gain a victory over the Jags looks like this....
.75 X .7 X .7 = .37 The slightly lower odds of winning in the first two games reflect the impact of travel on the first two games, and the Sharks also not having to travel but prepare at home. But with the certainty of a home final....37 % then.
There is, however one more wrinkle, the chance of the first team still losing against the Jags after a long flight and with the Jags really up for blood in their last game. That has to have been about 30%...which takes the beat the Jags probability to .37 X .7 + .06 X .3 = 28% The latter small adjustment is for a full hearted Jags effort still resulting in a loss, but the remaining games won....a 2 % probability.

So there you have it, either approach yields a 27% to 28 % probability of winning the cup. Throw in the risk of potential injuries to key players in Bargie and Ackerman's decision is totally rational.
Of course the 50% hope the Canes would stumble has been lost, lowering the Lions odds of winning....but only from 27% to 20%. But that is Monday morning quarterback stuff. At the time both paths had about an equal chance and Ackerman went for the surer option of actually getting to the final. 
I was negative about his decision, but having run the numbers I would have made the same choice.

 Mozart - How do you get to the Lions having a 20% chance against the Hurricanes? I think - taking into account home ground advantage for the Hurricanes it looks more like a 45% chance.

 History and the betting odds. The Lions pay 2.9 to the Canes 1.3. In any case these are illustrative numbers, adjust them slightly and the conclusion doesn't change materially.

 History of this year or previous years?  I am not interested in odds - if that was in any  way a reliable norm to go the favourites will always win.  By the way the Hurricanes has never won the Super Rugby trophy - last year they came in as heavy favourites and lost against the Highlanders.   I will look at all results involving the Hurricanes and the Lions in teams the two side met and come back to you. this year and come back to you 

 All that raising the odds does is make the headline point more true....but you are welcome to your views. If you really believe them put a big bet on the Lions.

 I did put a net on the Lions at 19-10. 

 Good Luck. Watch those netted Lions though, they can be dangerous.

 Stats mean nothing to me at the best of times ... and even less so in the knock out stages of the competition. This is finals rugby. 
It's using what happened today to thumbsuck a possible outcome for tomorrow and then foolishly putting money on it.. 
To me the vibe in the team tells a story. Their attitude. Their confidence. What we've seen all season long ... not a sudden surge of positiveness today, but what's been built systematically over the last few years.  
I feel that the Lions have an excellent chance to bring the trophy home. 
We are hungry, we are determined and we have an attitude in the side such as I haven't seen in any South African team for many moons.
We have a belief ... and so do I.
Go ahead ... write us off. 
Lions by 5.
Gooooooooooooooooo Lionssssssssssssssssss!!!

Who has written the Lions off?

 A 30% chance is not really showing much confidence is it?
Would you put money down on them with those stats?
I would but then again I'm being led by the heart and a gut feel. 

 All I was doing was reflecting consensus views of games, as best I could find them.....using those to build a probability model that said Ackerman's choice to not send his best team against the Jags was rational at the time.
To do that I have reflected what seems to be the betting view on Saturday's match....not necessarily my own view.

A few years back I built a predictive model for the Test season and wiped the floor with the opposition. But I never enjoyed watching the games having rationally betted against the Boks....so I never did it again, and just enjoy the rugby.

The Canes have to be favourites based on a host of factors, but we are dealing with a Leicester City scenario....the Lions have  a real chance.

 I see.
I agree ... we have a shot ... a good shot.
Can't wait.

Nice math Moz, but I don't buy it.
Dumb move by a good coach.
Jags have been out of sorts all year, winning essentially a formality for an in form Lions team. Then to come home to an inept Sharks outfit would have been no challenge. Would have maybe required 50 min games from starters at the most. Even selectively resting starters, or rotating them to the bench in both games would have been more strategic and achieved the same goal. 
Ackerman traded travel before a QF match against the Sharks for travel before the Final against the Hurricanes.
Biggest problem with it is the forfeit of home ground advantage. Lions have the best home ground advantage in all of rugby, especially against the high pace NZ teams. It is no coincidence the best Bok performances have come at Ellis. There is no substitute for an advantage that nullifies the superiority of the opposition. NZ superior fitness and pace of play isn't a factor when you're playing against an acclimatized team that is willing to meet you and then raise the ante.
Lions have the intangibles to overcome the challenge though. Maybe that's what Ackermann was banking on - and why he's a good coach.

 Perhaps Matey. But if you say the Lions were 90% likely to beat the Jags and the Sharks....the odds they would beat the Jags and win their next 3 games is only 42%. 
You make an excellent point on Ellis Park .....I'm sure Ackerman never thought the Canes  were going to go through the 3 top NZ teams in sequence.

 Always easy to be wise after the fact.  The squad was announced before the last round of Super Rugby was played.   There could have been no certainty that the Hurricanes will end up on top of the log by getting a bonus point win in Round 17 and end up as the top log leader.   If the Hurricanes did not get that bonus point, they would not have topped the log.   If all factors were known Ackerman could have made a different decision, but how was he to know?      

What Ackerman "knew" was that if they beat the Jags, they get home field advantage for the whole playoffs. 
Guaranteed.
The minute he decided to roll the dice on the Jags game he relinquished control of their destiny. I would never have done it. Situation is exacerbated by the predicted weather for the final, whereas a dry fast track is close to a sure thing this time of year in Joburg.
Really hope he proves me wrong though !
I see it coming down to battle of flyhalfs. Barrett is a superior tactical kicker. Hurricanes rush defense stymied Jantjies last time. Massive emotional effort from Jantjies on Saturday - one of the best sporting moments all year, but the emotion and adrenalin dump afterwards is hard to cope with.

I said at the time and maintain it was a mistake. Like Oimatey says- he could have ensured that all remaining games were to be played in South Africa. 
Any New Zealand team that had a mathematical chance of winning the tournament playoffs this year- would be hard to beat in a final away f rom home.
The Sharks game was the time to rest players- after putting the game beyond doubt. 

 I think the only NZ team we could have faced away from home was the Canes. Ackerman took a bet they wouldn't make it through 3 straight games, he lost. But if he never took that bet there were the other risks outlined above. 

I think Ackermann was too strewd to underestimate the Argies at home with a B team but took the best option at the time...yes he played a wild card but he also knew he had to have his best team available to finish the job...you cannot burn the candle at both ends.

He has built a confident team that can climb mountains and his faith in his players has built players that play at their full potential...Elton's talent has thrived under his direction...giving him direction to play to his initiative unlike AC who nearly destroyed this lad's career when in Cape Town...and Elton is not the only one...in fact it is true with the bulk of the Lion's team.

Cannot wait for this final...I believe they will rise far beyond expectations and travel factor. Go Lions and show them what you are made of...do it against the odds.

 You guys speak as though a Lions win over the Jaguares was a sure thing.
We could still have come away with a loss ... and a whole lot more. Injured players, food poisoning and a team not as well rested as they currently are.
He put his trust in our 2nd stringers and they gave it their all. I was very proud of their effort. From it came a player like Mahuza. 
In the end it's 6 of one and half a dozen of another. Hindsight is an exact science. 
Ackerman chose to follow what he thought was best and I don't have any issues with it. I am most certainly not going to throw my toys out if we lose ... but you better believe that my celebration will take on new found heights if we were to win.
Goooo Lionssssssssss!!!!!!

 

I agree, sending even a A side was no guarantee against a side that blows hot and old...and yes if they became defeated in Arg. would have put full recovery impossible.

A good decision, Mr Ackermann...at last a coach who knows how to make good decisions.

Oh well, No Ellis Park, No Home Crowd advantage, No altitude and then there is the travel factor   - what will Jantjies do? will he perform or will he wilt.

Remember, Jantjies and your number 9 will be harrassed at every turn, your wings will be given no space. Your scrum will be targetted.

 Well I'm pleased that you've at least acknowledged that the odds are stacked against us. 
The Canes should thrash us ... right?
And if they don't? What then, Poef?

 Our scrum will be targeted....by whom, the ref? 

 Glen Jackson has been especially briefed for the occassion

And even if the Lions win we are determined not to believe the scoreboard but will concort all sorts of conspiracy theory to explain

Well that's a relief, for a moment I thought you had taken so much strain after the Lions destroyed those two pansy teams...Saders and Landers....that you actually thought a NZ scrum could be an offensive weapon. But no...that's just silly.

only a few hours left Mozart - u up for it? I say bring it on. Come at us Lions.

Throughout the game I kept on thinking, feck, this game could've been played at Ellis Park . For the Argie game Ackers should've filled his bench with his A team bringing em on when necessary .

 Dr Moz could you please do a calc showing why akkers got it wrong. I know you stats people are very capable. hahahahahahaha
I have this morning read an article as to how polls are manipulated in the USA elections. One company can actually predict what these globalist pollsters will be predicting they are so predictable as they are into manipulation not news.

 Good old Ackers.Another in a long line of thick SA coaches....

 Looks like a dumb decision now but I guess he knew the Jags would have humiliated his A team so best play it safe Moolaa

 All ackers needed was his top players coming off the bench for say 20 minutes and it was a home final.Beeno of  course called it right.I trust the good Dr Mpz will not find his new task too problematic!!
Meanwhile could the hapless mooo la la of the moon light night fame and poor JW please go and study  the offside laws! Bwhahahahahahahaha

 Sounds like our mate Glen did a good job, we can always rely on kiwi refs Beeno. In my considered opinion they should ref all games, this would ensure we get the consistency we are all looking for

 Glen reffed a fair match, but made a few errors both ways....par for the course. Best NZ reff.

This was a blunder of epic proportions by Ackerman. He actually mentioned during the week that this was probably a mistake. Oh well, allways next year.....
The Lions again struggled with the Rush Defence. Jantjies was not given space- and did not have the type of game he is capable of.

 JW being best nz ref is no recommendation! Bryce lawrence was nz ref of the year no more need be said! 

 Good point Beenz, but Glen is streets ahead!