The F 35 is not going to be involved in dog fights. It is built to take care of enemy fighters from long range and so how it will perform in dog fights is really irrelevant.
It will definitely be involved in dogfights. They are not a thing of the past, every advancement in BVR technology, and people start assuming that closer range of engagement is a thing of the past, this is simply not true.
All aspects of a fight have associated with them, a list of probabilities, probability of interception by enemy radar, probability of detection, probability of a missile making its hit, probability of the enemy's radar and missile setting off your ECM equipment such as RWR and MAWS.
The F-35 should, in some engagements, may be able to fire away a missile against its target before being detected, and should therefore kill before it is killed. But stealth does not mean invisibility, it is making yourself seem too small, such that the enemy radar cannot differentiate between you and what it sees as clutter, thus you aren't painted as a valid target, until closer ranges, or your stealthier configuration is somehow compromised.
But, if you were to ignore all those technical details and jargon, suffice to say, the F-35 will not have it's way every time, and if it is against an as advanced target, they both may not be able to engage each other before reaching a closer range.
And in some engagements, the F-35 may not have a chance to make use of BVRAAM, and may be forced in a dogfight, take for example the Israelis, if one day, an F-35 is scrambled to respond to one aircraft passing through a buffer between the enemy territory and international boundary. Now, towards the north, at it's narrowest, Israel's geographical depth is barely 50km. From some airbases the border is barely 30km. And in the short amount of time that the F-35 takes off, precious moments are lost with the intruder closing in. If the intruder is closing in at mach 1, even 30 seconds amounts to 10km travelled. As you can see, depending on what sort of engagement the F-35 is placed in, it may never be able to use it's BVRAAM. A similar problem we had here in our neck of the woods, some bases of ours and the Indians, are not that far at all from the border, and to intercept a target closing in fast, WVR may be the only option. There are of course other situations where this may be the case too.