We have the first of two back-to-back, snack-sized rounds this weekend where only two-thirds of the teams get to take the field across a four-day span.

Five of the six games are expected to be decided by less than 14 points, the only potential blowout the Friday night game that pits a 7 and 4 Port Adelaide against a 4 and 7 Western Bulldogs that were, for a time, 4 and 4.

Overall, the average expected margin has come in at 14 points per game, which is the lowest it's been for a Round 13 since at least 2012 and is the fourth-lowest average for a single round this season. It takes the season average to 17.1 points per game, about a point less than the average across the entire 2017 home and away schedule, and almost eight points lower than the average for 2016.

This year and last have, in fact, promised much lower average margins than any of the five seasons that came immediately before them.

Unfortunately, unlike last year, actual margins have not this year delivered on that expectation of closer games, with average victory margins of over 30 points per game in each of the last five rounds and over 40 points per game in three of those.

All told, the average margin has been almost 37 points per game, which is over five points per game higher than the home and away season average for 2017, and only one point per game less than the averages for seasons 2015 and 2016 when the expected margins were far higher.

Just three rounds in 2018 have seen an average victory margin below 30 points per game. By this time last season there'd been five, and no single round had seen an average above 42 points per game.

TIPS AND PREDICTIONS

There's not a great deal of disagreement amongst the Head-to-Head Tipsters this week, with only Consult The Ladder (twice), Home Sweet Home (thrice), and C_Marg (once) preferring underdogs over favourites. That will leave the top of the Leaderboard unchanged come round's end.

Amongst the Margin Predictors we see generally high levels of agreement as well, though MoSSBODS_Marg is relatively bearish on the home teams' chances in five of the six contests.

In comparison to the current leader, Bookie_Hcap, a best set of results for MoSSBODS_Marg would see it move from about 83 points behind to 39 points behind, while a best set of results for MoSHBODS_Marg would see it move from about 114 to about 84 points behind.

At the game level, only the Suns v Saints, and Cats v Tigers game have generated other than small mean absolute differences (MADs), the MADs for those two games coming in at about 5 points per Predictor.

The mean expected margin across the seven games this week and all Margin Predictors is 14.4 points per game, which is, as has been the norm this season, slightly above the TAB bookmaker's average,.

Turning lastly to the Head-to-Head Probability Predictors we find a large range in the probability estimates only for the Gold Coast v St Kilda game where C_Prob and the MoS twins in particular have startlingly divergent views, C_Prob going as far as to install the Suns as narrow favourites.

Altogether, we have MoSSBODS_Prob as the Predictor most extreme in five contests, C_Prob in three, Bookie_LPSO in two, and Bookie_OE and MoSHBODS_Prob in one each.

WAGERS

Investors have wagers on only half of the weekend's games comprising three head-to-head and two line wagers.

(Please click on the image below to access a larger version.)

St Kilda has the two largest wagers of the round and Richmond the two smallest, a fact that is reflected in the ready reckoner, which quantifies the week's wagers' individual and collective risk, and appears below.

The swing in the Suns v Saints game is over 4% and could be triggered by as little as two late goals either way.

In total, just over 4% of the original Combined Portfolio is at risk and the maximum upside is 3%, the excess of risk over reward an inevitable consequence of having five wagers at less than even-money odds.

To finish, here are MoSHBODS' and MoSSBODS' opinions about likely team scoring.