So 5. Be3 and 5. Bb5 look both quite good for black. 

What about the normal 5. Nf3 then ? Could it be the best white possibility now ?

I've been doing a bit of database digging in this line, and it's starting to interest me more. I like to have a few variations up my sleeve in the slippery Pirc.

Firstly, I looked at 1 e4 Nc6 and the report gives it scoring above average for Black at 47%! However there's a severe lack of GMs using it at all currently. I think it would be only Tony Miles, if he was with us Today. Why that is, is a question for another thread. 

However one interesting name in the report was Zvonimar Mestrovic. What? You've never heard of him? Well he's a Slovenian IM who's been playing 1. e4 Nc6 2. d4 d6 and 1. e4 Nc6 2. Nf3 d6 since 1977 to present and has scored 87.5 / 139! So there's some reward in specialisation and enough games there to work out a repetoire.

As for the line in question, well White is only scoring 51% with 8 h3 and the main replies are c6 (62) and e5 (37), both scoring 49%. But there is also c5 (8) with 44% and Nbd7 (9) with 39%. You have to be careful with the statistics though as there aren't many games in my DB in this line (numbers are in brackets above). 

However I've got White scoring 66% in 67 games with 8 Re1, but again not a big sample. The GM chosen move is 8. ...Bg4. Logical to offload a minor piece with the space disadvantage, and Black scores an average 44% here. But c6 (with a6, cd, and b5), e5 (with an eventual d5 break after de) and even the little played Nbd7 all look like decent attempts to equalise. 

As for 8. a4, well even less games, and the usual tiny edge for White. Interesting is that it was Tony Miles choice as White against Quinteros in 1986 (Miles won). Plan for Black seems to be 8. ...a5 and then Nb8-Na6-b4, a thematic way to develop the QKnight against a4.

In conclusion, I don't see any major problems in these lines, well no more than you'd get in other defences, and I'd say this line is well worth a punt at any level 

The Carpathian Warrior only covers Austrain lines, nothing classical. The issue with the early commitment of Nc6 is that White has chances to kill the game off into positions with little winning chances, especially for Black. 

I used to think this was a problem, however I like the classical positions, play both sides of them, and score well with Black. Theoretically I don't see White getting more than the normal tiny plus thats obtained in other mainline openings, and middlegame experience will tell more in this line IMHO. 

As for 6. ...Nc6, I'll quote Gallagher in Starting Out Pirc/Modern "generally considered to be the least trustworthy of Blacks mainstream 6th move alternatives, but as we shall see it is better than its reputation".

He gives 6. ...Nc6 7. d5 Nb8 8. h3 as the line that puts some Black players off as Black has less space and a full set of minor pieces.The line runs 8. ...e5 9. de Bxe6 10 Bg5 h6 (important to play h6 before White stops it with Qd2) and "Black would be facing uncomfortable pressure."  Still there's chances to equalise and you might like this Philidor like position.

Both Khalifmann (OfWatA) and the Ultimate Pirc give the 7. ...e5 line as a simplifying into a slightly better ending for White, which is sometimes a satisfactory evaluation for both players (eg the Berlin wall), ie Black might be able to defend it for a draw, but that's not for everyone. So both give 7. ...e6 as the mainline plan which is interesting as it doesn't crop up as a the mainline plan elsewhere. Draw your own conclusion from that. 

Playing battle of the books, Khalifmann follows the Ultimate Pirc lines and takes them at bit further (some were just assessed as unclear) concluding a slight advantage for white, however there is vast scope for improvments to be found for both sides. Quite virgin territory which has a big appeal. 

Here's a TN for you on Khalifmanns book 1. e4 g6 2. d4 Bg7 3. Nc3 d6 4. f4 Nc6 5. Be3 Nf6 6. Nf3 0-0 7. Be2 e6 8. h3 b6 9. g4 (is Black getting worried yet  ) Bb7 10 g5 Nh5 11 Rg1 Ne7 12. Qd2 f5!? which is a thematic retort to Whites f4-f5 plan, and now you're both on your own  

Here's an excerpt from Khalifmann's conclusion "The defensive system for Black that we have analysed in this chapter is very dynamic and requires from White energetic play right from the start" That's a pretty good endorsement!

From a quick DB survey, this move order has been popular with GMs for many years, and is still used. It scores averagely for black. I have no experience with playing it myself, but I looked at it a while ago because of some of the Pirc champs that have used it (Azmaiparashvilli, Benjamin, McNab, Nijboer, Keene and Davies is a pretty repectable list).

In the mainline Austrian with 6 Bd3 Nc6 (which has been growing on me lately), White usually ends up moving the Bd3 somewhere else (Be2 in the mainline anaylsis) suggesting that it isn't on the right square. With the Modern move order, if Black plays Nf6, White might be able to deploy this Bishop to a better one to get a favourable transposition (1. e4 g6 2. d4 Bg7 3. Nc3 d6 4. f4 Nc6 5. Be3 Nf6 6. 0-0 7. Be2) or play Bb5 as suggested, but that looks ok for Black too, in a Lopezzy kind of way.

Interesting that in the Ultimate Pirc, the recommendation is a Hippoesque setup with e6, Ne7, b6, Bb7, although the e5 line looks ok.

So yes, it's a respectable line for Black and handy to have up your sleeve, especially if you are happy with the Nc6 Pirc against the Austrian. White needs to have something against it and there's plenty of games to study.