Team News Model Adjustments: A Worked Example

In my earlier blog (“How do you use team news to adjust a model?”) I outlined a very basic technique to adjust model prices for team news using the Stratagem player ratings. I will now put this technique into action and look at a specific upcoming Scottish Premiership match:

Heart of Midlothian v Dundee United
Scottish Premiership
Wednesday 30th December 2015

StrataBet Model Projections: SUP 0.73, TOT 2.89

Our first step is to look at the strongest eleven of each team and separate into the Defensive Unit and Attacking Unit:

TeamNewsExample1.png

Supremacy Adjustments
Using the StrataBet Preview for the match, we can see that Juanma ST3 is suspended and Walker RW/AM4 injured, meaning there will be two negative adjustments on the Attacking Unit.

Reilly ST1 and Pallardo DM2 are the players expected to start, so by taking the difference between the ratings, multiplying by 2 and dividing by 100, we get:

DM2-RW4 = -2 x 2 / 100 = -0.04
ST1-ST3 = -2 x 2 / 100 = -0.04

With Hearts playing a big match against Celtic on Sunday and Dundee United’s game with Motherwell postponed, there should be a small negative adjustment made to Hearts to reflect this.

As is often the case with teams playing in the Europa League on a Thursday and then in their domestic competition on Sunday, it can be struggle to adapt to having only 2 days between fixtures.

Not only are the players likely to be fatigued, the lack of time to plan tactically for the next game can also be an issue. I would deduct an arbitrary -0.03 for each unit, adding -0.06 onto Hearts’ Supremacy:

Hearts Supremacy Adjustment = -0.14

Total Goal Adjustments
With both negative adjustments for Hearts coming from the Attacking Unit, this will have a negative impact on our Total Goal quote. We use the same calculations as the Supremacy Adjustments here:

DM2-RW4 = -2 x 2 / 100 = -0.04
ST1-ST3 = -2 x 2 / 100 = -0.04

Hearts Total Goal Adjustment = -0.08

TeamNewsExample2

Supremacy Adjustments
From the Preview, Sinama-Pongolle SS2 misses the match through injury, but it would have been a manager’s choice decision between him and Erskine AM/RM2 to start, so no adjustment is required.

Morris CB1 is keeping Souttar CB/RB3 out of the team in what is also a manager’s choice decision, and this also does not require an adjustment:

Dundee United Supremacy Adjustment = 0

Total Goal Adjustments
With no player changes of note, there is no Total Goal Adjustment:

Dundee United Total Goal Adjustment = 0

Long-Term Adjustments
Dundee United are still affected by losing three very important players in the summer, and despite the significance of these players decreasing as time goes by, there are still some residual adjustments to be made.

Cierzniak GK4, Fojut CB4 and Ciftci SS4 all departed and it has been evident that these players have not been sufficiently replaced. McKay ST4 has not hit the ground running and is still struggling for form, despite being the only striker of any quality at the club.

I would suggest that McKay’s ST4 rating is due in part to the lack of alternatives rather than form of the player. While in defence and especially in the goalkeeping department, United have had a terrible first half of the season.

Hearts on the other hand arguably improved over the summer, while keeping the nucleus of the team that comfortably won the Championship. They replaced Zeefuik ST3 with Juanma ST3, and Wilson CB4 with Augustyn CB3.

It is also worth noting that the departing players were playing at a level below the Premiership, so in my view these changes do not merit a negative adjustment.

Hearts
As discussed, I do not see any residual Long-Term Adjustments needed for Hearts.

Dundee United
For the sake of this example, and using hindsight to judge the loss of quality on the team this season, I will assume each of the three player departures in the summer have been replaced by a “2” rated player, and adjust for time decay:

Cierzniak: GK2-GK4 = -2 x 2 / 100 = -0.04 (SUP) and +0.04 (TOT)
Fojut: CB2-CB4 = -2 x 2 / 100 = -0.04 (SUP) and +0.04 (TOT)
Ciftci: ST2-SS4 = -2 x 2 / 100 = -0.04 (SUP) and -0.04 (TOT)

With each team having played 19 games so far, we are exactly half way through the Scottish Premiership season, so I will multiply the totals by 50% to get today’s decayed Long-Term Adjustment:

Hearts LTA = 0

Dundee United LTA = -0.12 x 50% = -0.06 (SUP) and +0.04 x 50% = +0.02 (TOT)

Other Adjustments
Although rain is forecast throughout the day in Edinburgh, it appears this will clear up as kick off approaches.

The Tynecastle pitch will no doubt be wet, but it is holding up well in the current weather, and should not deteriorate throughout the match. We will not make an adjustment for a poor pitch or weather conditions in this case.

Adjusted Supremacy and Total Goal quotes
Having now accounted for most things that the model does not include, we can settle on our final Supremacy and Total Goal quotes and compare to the market:

Supremacy: Starting Quote + Hearts Adjustment + Dundee United Adjustment
= 0.73 + (-0.14 + 0.06)
= 0.65

Total Goal: Starting Quote + Hearts Adjustment + Dundee United Adjustment
= 2.89 + (-0.08 + 0.02)
= 2.83

SUP

TOT

Adjusted Model

0.65

2.83

Market Actual

0.65

2.55

Comparing our new figures to the market, we are almost in line. Unless the Overs drift to 5% greater than our own price, then we will not place a bet in this match.

Mark McAfee