Today, for the first time ever, the TAB refused to accept a MAFL bet.

Motivated, perhaps, by a desire to protect me from accidental stupidity but, more likely, by a concern that its initial market price was excessively generous, the online TAB site initially prevented me from placing a wager of the size I requested on the Giants at $17. Instead, it politely suggested that I place a wager about one-half the size I'd input - a politeness that rapidly morphed into intransigence when I insisted on my original stake. The computer, apparently very firmly, says no.

A couple of hours later the TAB relented, allowing me to place a wager at the same price for the remaining amount, and so it is that Investors have about 4.3% of the Head-to-Head Fund riding on the Giants on Saturday, a win by which would represent the largest single-wager return in MAFL history (and might well precipitate porcine aviation history).

Almost as audacious are the Head-to-Head Fund's wagers on the Suns at $6 facing the Pies, and on the Crows at $4.90 facing the Cats. These two head-to-head wagers, along with the wager on the Giants, are joined by another, far more conventional bet of very modest size on the Tigers, facing Freo, at $1.95.

Accompanying that quartet of head-to-head wagers are four line bets, three on the same teams selected by the Head-to-Head Fund - the Tigers being the exception - and a fourth on the Dees receiving 30.5 points start playing the Lions.

Four SuperMargin wagers complete the week's activities, all but one on uncontroversial victory margins and so enjoying unremarkable prices, and the fourth on the Hawks winning by just 10 to 19 points over the Dogs, considered a most likely outcome, and so carrying a $17 price tag.

That leaves Investors exposed to the outcome of seven of the week's games and with markedly different 'care factors' across these seven. In four games the maximum upside is over 2.5c, most emphatically in the Giants v Dons game where it's over 23c. Elsewhere, Gold Coast or Adelaide wins would be worth almost 5c, whilst a Melbourne loss by 30 points or fewer would be worth about 2.7c.

Four games carry the majority of the downside risk, with unfavourable results for Gold Coast, GWS, Melbourne or Adelaide, all putting at least 3c in the TAB's pocket.

TIPSTERS AND PREDICTORS

Only two home teams are favourites this week, and only one of them is the majority pick of the MAFL Head-to-Head Tipsters, leaving Home Sweet Home (HSH) in the minority in every game except the Hawks v Dogs clash. In the seven games where the away team is the favourite, no more than one other Tipster has joined HSH in selecting the upset.

Two games have split the Margin Predictors: Friday's Roos v Blues clash, which sees eight Predictors foreseeing a home team win and eight an away team victory, and Sunday's Tigers v Freo clash, which sees six Predictors favouring the home team, and 10 the away team. Even in those games where Predictor opinion about the likely winner is more aligned, however, in most there's a marked lack of confidence. In all but two of the week's games the standard deviation of the Margin Predictors' margin predictions is in single digits.

The Head-to-Head Probability Predictors are also split on the same two games as the Margin Predictors, with the most directly Bookie-based Predictors all siding with the Roos in their clash with the Blues, and the remainder of the Head-to-Head Probability Predictors instead finding favour with their opponents; and with the H2H and Bookie LPSO Predictors selecting the Tigers over Freo, and the remaining Predictors coming down narrowly on the side of the Dockers.

On line betting, the Line Fund algorithm rates four home teams as favourites, all of which it's sufficiently confident about to result in wagering activity. In the remaining five games the algorithm rates the away team as the more likely line betting victor, with probabilities ranging from 53% (Carlton) to 64% (Western Bulldogs). The Dogs and the Suns are the only teams rated by the Line Fund algorithm as better than 60% chances of winning on line betting.