Catching up? Here's what you need to know about Australian GP Friday practice

* Lewis Hamilton was fastest in both of Friday's practice sessions but P2 in particular provided encouragement that a close fight at the front will emerge with Red Bull barely a tenth of a second adrift of Mercedes and Ferrari only fractionally further behind.

* Red Bull were half a second slower than Mercedes in Practice One but improved considerably in Practice Two with Max Verstappen separating Hamilton and Valtteri Bottas. Daniel Ricciardo's push to join the front was wrecked by a red flag during his low-fuel flying lap.

* But Ricciardo will receive a three-place grid penalty for Sunday's race after being adjudged to have gone too fast under red-flag conditions during Practice Two. The FIA claim the Red Bull driver misread his dash and "did not stay above the minimum time set".

* Ferrari currently look the third fastest outfit but Kimi Raikkonen finished P2 just three tenths behind Hamilton. Sebastian Vettel failed to hook up his flying lap and couldn't maintain his pace into the third sector on his second flier.

Practice Two timesheet
Practice One timesheet

* On the long runs in P2, Mercedes and Red Bull once again looked closely matched with Ferrari slightly behind.

* Despite McLaren suffering more mechanical issues in P1 Fernando Alonso was eighth quickest in both sessions.

* Judging by social media comments, the halo isn't universally popular!

* Haas made good on their promising performances in winter testing with Romain Grosjean seventh in Practice One and sixth - ahead of Ricciardo after the Australian's flier was halted - in Practice Two.

* Renault were subdued and appear to be behind Haas and potentially McLaren in the battle to be 'the best of the rest'. Carlos Sainz was faster than team-mate Nico Hulkenberg in both sessions.

* Sergey Sirotkin struggled for outright pace and was nearly half a second down on Lance Stroll in Practice Two.

* The midfield looks particularly congested. A second of lap time covered the seventh-placed Grosjean to the 16th-placed Stroll in P1 and there was less than a second between Alonso in eighth and Pierre Gasly's 17th-placed Toro Rosso in P2.

* Heavy rain is forecast for Saturday's qualifying hour (which begins at 6am UK time).

* Ferrari boss Maurizio Arrivabene and Red Bull counterpart Christian Horner clashed off track over the Scuderia's appointment of former FIA man Laurent Mekies.