Preview of AFL round 15 games (all times local).

FRIDAY, July 10
WESTERN BULLDOGS v COLLINGWOOD at Etihad Stadium, 7.40pm
Head to head: Western Bulldogs 41 Collingwood 99 Drawn 1
Last time: Western Bulldogs 15.9 (99) bt Collingwood 13.11 (89) R13, 2008, Etihad Stadium
TAB Sportsbet: Western Bulldogs $1.55 Collingwood $2.40
Sportingbet: Western Bulldogs $1.60 Collingwood $2.35

Last Sunday’s classic encounter between St Kilda and Geelong was the clash of the titans and this is the clash of the challengers. Together with Adelaide, the Bulldogs and Magpies appear the sides most likely to crash the Saints and Cats’ September party. The `Dogs have strung five wins together and the Magpies six. Both were very impressive in their last outings – the `Dogs annihilating reigning premiers Hawthorn while Collingwood outplayed in-form Essendon. But with both sides having mostly beaten lower-ranked teams, they will both be keen to prove their credentials against strong opposition. The Bulldogs have won five of the past six meetings between the two, mainly by running the Magpies off their feet. But Collingwood have worked hard to improve their midfield depth and pace and this match will provide a good guide of how well it has worked.

Key: Collingwood forward-cum-midfielder Alan Didak has been in the form of his career, racking up 30-plus disposals four games straight, having never previously done so. Tenacious Bulldogs tagger Liam Picken has cut down some big names in his debut season and could be handed the important job.

Tip: Western Bulldogs by 10 points.

SATURDAY, July 11
SYDNEY v ESSENDON at SCG, 2.10pm
Head to head: Sydney 78 Essendon 128 Drawn 1
Last time: Sydney 21.17 (143) bt Essendon 7.10 (52) R8, 2008, ANZ Stadium
TAB Sportsbet: Sydney $1.60 Essendon $2.25
Sportingbet: Sydney $1.67 Essendon $2.20

While Sydney are yet to win away this season, their 6-1 record in home games, including 4-0 at the SCG, makes ominous reading for the Bombers. Essendon’s biggest strength is their pace, which has allowed them to cut up several opposition teams in the second halves of matches by running them into the ground. But on the small SCG that tactic will be less effective. The Swans’ strength of slowing the tempo of games, ensuring plenty of stoppages and winning the hard ball will come to the fore. That makes the fitness cloud over the Bombers’ No.1 ball-winner Jobe Watson, who missed last round’s loss to Collingwood with an ankle injury, particularly significant. Despite the uncertainty created by Barry Hall’s temperamental outbursts, his marking power in attack will be missed by the Swans. Essendon’s big forwards Matthew Lloyd and Scott Lucas have been in decent form and it might be one area the Bombers have an edge.

Key: Athletic Essendon youngster Paddy Ryder has impressed in the ruck since David Hille went down injured on Anzac Day, but showed signs of tiredness against Josh Fraser last round. He faces another big test against Sydney’s Darren Jolly and if the big Swan dominates the hit-outs, his team’s midfield could control the game.

Tip: Sydney by 10 points

CARLTON v RICHMOND at MCG, 2.10pm
Head to head: Carlton 116 Richmond 84 Drawn 2
Last time: Carlton 23.12 (150) bt Richmond 9.13 (67) R1, 2009, MCG
TAB Sportsbet: Carlton $1.25 Richmond $3.75
Sportingbet: Carlton $1.28 Richmond $3.75

Terry Wallace probably still has nightmares about the Blues’ 83-point win in the much-hyped season-opener in front of nearly 87,000 spectators at the MCG. It was a blow from which the Tigers’ season and Wallace’s coaching career never recovered. There is not much left for Richmond to play for this season under the guidance of caretaker coach Jade Rawlings, with the main emphasis on cycling young players and fringe players through the senior side to work out who should stay on for next year. But if the Tigers could pick one game to win in the run home, exacting some revenge on the Blues and spoiling their finals hopes would probably be it. Carlton’s recent form has not been dazzling either. After being destroyed by Essendon in round 13, they just scraped past Fremantle last weekend. It is vital they win here, with much tougher clashes with Sydney and Collingwood to follow.

Key: The Blues’ midfield was in full swing in round one, with Marc Murphy, Bryce Gibbs and Chris Judd all dominant. Their midfield stars were again the key in their comeback against Fremantle last weekend and if they can reproduce that form against the Tigers it should be enough.

Tip: Carlton by 25 points

BRISBANE v GEELONG at the Gabba, 7.10pm
Head to head: Brisbane 16 Geelong 17 Drawn 1
Last time: Geelong 18.18 (126) bt Brisbane 5.3 (33) R5 2009, Skilled Stadium
TAB Sportsbet: Brisbane $3.35 Geelong $1.30
Sportingbet: Brisbane $3.30 Geelong $1.34

The 93-point hammering the Cats handed the Lions last time the two clubs met prompted Brisbane to do some serious soul-searching. Their resolve not to reproduce that sort of uncompetitive performance has resulted in them turning their season around. In the eight rounds that followed, their only two defeats were a 16-point loss to St Kilda and a six-point loss to Carlton. Their only serious blemish since came against Port Adelaide last round, when a terrible last quarter consigned them to an eight-goal defeat. Coach Michael Voss will no doubt be using the memory of that fadeout and their disappointing round five showing against the Cats to ensure they hit this match at fever pitch. Geelong might be vulnerable to a letdown after suffering their first defeat of the season against St Kilda in a ferocious encounter last round. But the Lions’ chances of an upset will be hurt by the loss of athletic utility Jared Brennan, suspended for headbutting Port Adelaide’s Josh Carr.

Key: Mitch Clark will carry a heavy load in the ruck given Brennan will not be there for support and if the Cats get a big advantage in that area, their star-studded midfield could rip Brisbane apart.

Tip: Geelong by 35 points

ADELAIDE v FREMANTLE at AAMI Stadium, 7.10pm
Head to head: Adelaide 14 Fremantle 9 Drawn 0
Last time: Adelaide 15.14 (104) bt Fremantle 11.14 (80) R3, 2009, Subiaco
TAB Sportsbet: Adelaide $1.12 Fremantle $5.75
Sportingbet: Adelaide $1.16 Fremantle $5.25

Fremantle have frequently been competitive in their recent matches, leading Geelong and Carlton for large portions of games in two of the past three rounds. But with an extremely inexperienced side, they have been unable to seal the deal and find themselves on a seven-game losing streak. By contrast, Adelaide have been pushed hard in several recent games, but keep managing to pull away when it counts, helping themselves to a six-game winning run. That disparity at the business end of matches is likely to be even more pronounced given this clash is at the Crows’ home ground and the Dockers have shown much more spirit at home than away. Underlining Fremantle’s youth and inexperience, they are set to field their 10th debutant of the season, quick midfielder-forward Tim Ruffles. Matthew Pavlich is still out injured, making it hard to imagine the Dockers producing an upset.

Key: Tall Adelaide youngster Kurt Tippett has become vital to the Crows’ structure. He kicked a match-winning five goals against Richmond last weekend and will also be needed this week for ruck support against Fremantle giant Aaron Sandilands.

Tip: Adelaide by 38 points

SUNDAY, July 12
HAWTHORN v NORTH MELBOURNE at Aurora Stadium, 1.10pm
Head to head: Hawthorn 87 North Melbourne 73 Drawn 2
Last time: Hawthorn 19.9 (123) bt North Melbourne 10.9 (69) R3, 2009, Etihad Stadium
TAB Sportsbet: Hawthorn $1.45 North Melbourne $2.65
Sportingbet: Hawthorn $1.47 North Melbourne $2.20

The Hawks have lost their past three games, including last round’s humiliatingly uncompetitive performance against the Western Bulldogs. It has caused them to sink to 11th on the ladder and prompted suggestions it is time to accept their premiership defence is over. But outwardly, at least, they maintain that this season is not beyond redemption. And given they remain just one win and a large chunk of percentage out of the top eight, if they can turn their form around a finals berth remains achievable. But it makes Sunday’s clash with the Kangaroos an absolute must-win encounter. North have battled hard for close losses against the Western Bulldogs and Sydney in the past two rounds and will view this as a decent chance to post their first win under caretaker coach Darren Crocker. But hurting their hopes is the loss of tough defender Daniel Pratt to suspension, while midfielder Daniel Wells remains absent through injury.

Key: Star Hawks forward Lance Franklin had a horror night against the Bulldogs, breaking a streak of 71 games in which he has notched at least one goal. If he cannot improve, the Kangaroos will be in with a good shot.

Tip: Hawthorn by five points

MELBOURNE v PORT ADELAIDE at the MCG, 2.10pm
Head to head: Melbourne 8 Port Adelaide 11 Drawn 0
Last time: Port Adelaide 22.15 (147) bt Melbourne 14.6 (90) R3, 2009, AAMI Stadium
TAB Sportsbet: Melbourne $2.80 Port Adelaide $1.40
Sportingbet: Melbourne $3.00 Port Adelaide $1.40

It took the news that their president is battling cancer to inspire the Demons to break a run of bad losses and defeat West Coast last round. Melbourne showed admirable zeal to post an emotional win for Jim Stynes at the MCG. But it is worth remembering the Eagles have not beaten anyone away from Perth since 2007, so it should not be taken as a sign the Demons are about to surge off the bottom of the table. Melbourne will also be without hard-nosed midfielder-forward Colin Sylvia, who has been in great form but is now serving a three-match striking suspension. The Power returned to form with a big win over Brisbane last round, which has them outside the eight only on percentage. They will have plenty of incentive, as they need to post wins over the Demons and the Eagles in Adelaide next round to position themselves for an assault on the finals.

Key: The expected return from injury of Power star Chad Cornes will further boost the confidence of a side already buoyed by their win over the Lions.

Tip: Port Adelaide by 25 points

WEST COAST v ST KILDA at Subiaco, 2.40pm
Head to head: West Coast 20 St Kilda 14 Drawn 1
Last time: St Kilda 25.11 (161) bt West Coast 9.10 (64) R3, 2009, Etihad Stadium
TAB Sportsbet: West Coast $5.00 St Kilda $1.15
Sportingbet: West Coast $4.50 St Kilda $1.20

The Eagles will be hoping it is time for St Kilda to have a drop in intensity, after 14 straight wins, highlighted by last round’s wonderful victory over Geelong. But given the steely attitude of the Saints all season that seems extremely unlikely. The biggest obstacle for the Eagles will be overcoming the Saints’ consistently ferocious defensive pressure. West Coast have struggled to kick big scores in most of their games, with a heavy reliance on talented small forward Mark LeCras for their goals, while the Saints have not conceded 100 points in a game all season. But that will be far from their only hurdle. The young Eagles midfield will find it hard to compete with the likes of Lenny Hayes, Nick Dal Santo, Brendon Goddard, Leigh Montagna and Luke Ball. And West Coast’s defence will have their hands full with in-form Saints key forwards Justin Koschitzke and Nick Riewoldt. Former Eagles ruckman Michael Gardiner will also be keen to impress after his match-winning performance against the Cats.

Key: If the Saints can avoid an emotional letdown after their long-anticipated clash with Geelong, West Coast will be in trouble.

Tip: St Kilda by 55 points