Handicapping Cubs Nationals 10/10/2017

And then there were six.  Here is what the betting markets think of the Cubs Nationals game today.

DATE 10_10 5:35_PM WAS CHN
LINEAWAY WAS [ 0.426 ] < 0.402 >
STARTAWAY -1.39(0.466) Tanner_Roark_WAS
LINEHOME CHN [ 0.592 ] < 0.615 >
STARTHOME 3.17(0.585) Jake_Arrieta_CHN
------------------------------------
WAS 97 65 CHN 92 70
DELTAWAA 10 WINPCT 0.582 WAS

We have seen irrational exuberance in the betting market from Cubs’ fans for regular season games at Wrigley before.  Since playoff games are national that exuberance should have less impact on the market.  Today the Cubs are favored with a 61.5% chance of winning.  If you think the Cubs have a higher probability of winning today than that, bet the CHN line.  If not.  Discard, don’t bet.

Winning at a 0.600 rate in baseball is high.  A team that wins at that rate in a 162 game season wins 97 games or a WAA=+32.  The Cubs desperately need this win to maintain home filed advantage and advance.  The Nationals are in survival mode.

Arrieta is a Tier 2 starter, Roark is Tier 4 for regular season.  Here are their playoff lines.

Rank WAA IP ERA Gs Gr Name_TeamID Pos
XXXXX -0.10 42.0 3.64 7 1 Jake_Arrieta_CHN PITCH  playoffs
XXXXX -0.06 7.0 3.86 1 2 Tanner_Roark_WAS PITCH  playoffs

These are two Tier 3 pitchers in the playoff season (although Roark doesn’t have enough playing time yet).    Washington can pitch Strasburg if Roark screws up and the Cubs have Montgomery, Hendricks, and maybe Lester or (god forbid) Lackey waiting in the wings.

Here are  lineup-starter combo pairs for this game.  WAS has a Tier 1 lineup, CHN  Tier 2 as shown many times in past matchup analysis of these two teams.

  1. 1-2 Tier 1 WAS lineup vs.  Tier 2 CHN starter  —:> 4.7 runs for WAS
  2. 2-4 Tier 2 CHN lineup vs. Tier 4 WAS starter  —:> 5.1 runs for CHN

I was supposed to finish the code yesterday to do these simulations but haven’t got it done, hopefully by NLCS.  Eyeballing these combo pairs the Cubs should be around a 55% chance of winning  giving WAS a 45% chance.  45% is higher than the market line for WAS of 40.2% but less than our margin.

If Arrieta has enough playing time to be considered Tier 3 playoffs that raises runs for WAS to 5.1 as well making this a 50/50 game for each team. If Roark is considered Tier 3 that lowers CHN runs to 4.9 perhaps tilting it into WAS favor albeit very slightly.

We know Arrieta’s career.  Here is Tanner_Roark’s career numbers to provide some more perspective on what the Cubs face.

Year WAA Name_TeamID Pos Rank
2013 3.0 Tanner_Roark_WAS PITCH +090+
2014 3.9 Tanner_Roark_WAS PITCH +053+
2015 -1.0 Tanner_Roark_WAS PITCH XXXXX
2016 6.4 Tanner_Roark_WAS PITCH +014+
2017 -1.4 Tanner_Roark_WAS PITCH XXXXX
Total 10.9

He had a somewhat bad season this year but an overall solid career.   His low this season was -2.0 around the beginning of July so he’s been mediocre second half of 2017.

Cubs have a better overall relief squad which is especially important in playoff games.  Cubs’ relief carried the team first half of the season, hopefully they can carry them into the NLCS today.

tl;dr CHN line a discard so all Cubs fans should not bet this game.  If you don’t care, WAS line is a don’t know, it depends.  This handicapping model has not been proven yet.