Quite easy for a thursday I thought, but I was left with a couple of quibbles and uncertainties. These were balanced by the highly enjoyable 9ac, 11ac and 25ac.
dd = double definition
* = anagram
< = reversed
Across
8. MANITOBA. MO(A NIT)B + A.
9. WHILE STOCKS LAST. Rotten tomatoes were thrown at people in stocks.
11. TRUST ME I’M A DOCTOR. MEDICOMUST(s)TART*+OR (=”on the other hand”).
12. GANDER. dd ‘bird’/’look’
14. AMORETTO. A + MORE + OTT<. An image of cupid (chubby naked boy).
20. UNDER PAR. A birdie in golf is an under par score, but to my mind ‘sick as a parrot’ means ‘disappointed and upset’, not literally sick.  I don’t have a Chambers or similar to see if it says different.
22. PRETTY.  dd ‘almost’ / ‘attractive’.
24. FAIR GAME. One might shoot ducks at a fair.
25. TRAIN. T(R)AIN ‘Right to enter TAIN’. Some people seem to think clues like this are somehow cheating, but I really enjoy them.
26. HEN NIGHT. HEIGHT is presumably measure up, but not sure why twins is NN.
Down.
1. CALABASH. C(A LAB(-our))ASH. A tree.
4. NATURAL. dd, presumably is a score in some sort of game (I dimly recall it being something in bridge and craps).
5. TWO-TO-ONE. T + WO(TOON)E.  Price in the betting sense.
6. PINE NEEDLE. PI(NENE + E.D.)LE. The Nene is a river.
7. KERMIT THE FROG. GREEKFOR+ H* around MITT. I’m not sure why ‘chand’ originally is H.
13. DUFFELCOAT. DUFF + TALE< around CO.
15. OPPOSING. OP(us). + POSING.
18. NOT RIGHT. dd. ‘left’ / ‘broken’.
19. BREATHE. B(RE:)ATHE.
21. NOTATE. Presumably ‘no tate’ but that assumes the tate  = Tate Modern, ignoring the three other Tate galleries that aren’t exclusively Modern art.
22. PATENT PENDING. PA(TENT)P + ENDING.
24. FLIP SIDE. Hidden in ‘oF LIPS IDEntifies’.
26 is bearing twins = NN
Fletch – I still don’t know why that’s NN!
Aaaah, the penny drops about ‘bearings’
Ciaran
7/15 – ‘chand’ is a misprint in the online version. The pdf version has ‘hand’.
4d – think musical ‘score’.
Great fun! I didn’t find this all that straightforward because of the large number of long solutions spread over the grid, but got there without too much trouble.
4dn: NATURAL as opposed to sharp or flat, in music – if a note in a key which would normally be a sharp or flat has to be played as a natural, there is an accompanying sign, or ‘scoring mark’
20ac: I think Paul acknowledges the imperfect definition ‘sick as a parrot’ by means of the question mark. The surface reads wonderfully.
9,23 is fabulous. How would one describe this clue – in which the solution is capable of being read in two different senses?
7/15 as the interpolated capital C immediately after an open quote also just happened to Araucaria, it looks like there may be a software bug at the guardian.
Thank you Geoff! I should have thought to check the PDF version. I’ll refrain from any Grauniad jokes, but the applet really is fairly shocking by modern standards.
I also should have realised the musical notation link in 4dn, having being forced into doing Grade 5 Theory in my youth – I was fixated on the ‘games’ angle.
Ah, yet another on-line typo! They must be doing it deliberately, the current apparent level of incompetence is not credible.
Never seen Duffel coat as one word before either.
Yeah, natural comes up in quite a few card games.
Overall, not being the unbridled genius that our blogger is, I struggled with this. But then I usually do with Paul, though I’ve done much better with him at times.
Is it possible that 20 across is a triple? If you are sick you feel under par and parrot is under par in the dictionary.
I thought this puzzle was brilliant by the way.
Geoff — that’s how I understood ‘natural’ too. Enjoyed 9, 23 and 11,3 especially.
I don’t mind clues like 25ac and this one made me smile.
Didn’t get 6dn, partly because I have never heard of Neve. Will try to remember that as a ‘flower’.
Agentzero – I was toying with the idea of sick=ROT and it’s under ‘par’ in the word PARROT, er, if you write it downwards. No, probably not.
Sorry, Nene.
Derek – Rather than being an unbridled genius, I suspect I just happened to guess the longish clues early on, which made the whole thing a bit more straightforward.
There are certainly enough supposedly ‘easy’ Monday and Tuesday puzzles I’ve started at with my mind blank to disprove the genius theory.
As my Dad likes to say, the only ‘hard’ questions are ones you don’t know the answer to.
Aha … Amoretto, I had amaretto in my head, and couldn’t see how “chubby naked boy” equated to the drink (altho it may be responsible for them runing around the paddock 😉 )
My favourite was “patent pending” … simple but clever.
Ciaran, I wondered about that too but I’m suggesting something different: that “birdie is”, “sick” and “as a parrot [is in the dictionary] are each separate defs of “under par”.
Ciaran
Re your query regarding 20a. Chambers does not list ‘under par’, only ‘below par’. Here are the entries from the usual references:
Chambers: below par – out of sorts, not particularly good in health, spirits etc
Collins: below or under par – not feeling or performing as well as normal
COED: nothing relevant
Derek
The pdf version had the enumeration for 13d as (6,4).
Ciaran
I have just realised that I misread your comment re 20a. Chambers defines ‘sick as a parrot’ as ‘extremely disappointed’ (as does Collins).
Ciaran, Geoff M, Agentzero: I think you’re all trying to read too much into 20ac. ‘Birdie’ in golf is certainly UNDER PAR, but ‘sick’ is more usually ‘below par’, and ‘sick as a parrot’ means something rather different (‘extremely disappointed’ is a polite version), so the clue is an iffy double definition. If it weren’t dubious, the question mark at the end would be redundant.
Well, I didn’t like this one at all, finding it really hard, and only getting half way after a very long time. I finally got 11a, 3d, and it helped me but little. The other long ones would just not pop into my head. So had to look up answers here.
I didn’t get UNDER PAR, despite thinking golf; nor 5d despite thinking betting.
I had better go lie down; I have another one to do tomorrow!
I was jiggered by this as I put in below par and couldn’t bring myself to change a clue that was obviously right. As I hadn’t much liked measure up as height and thought 6dn was a bit ropey, I just thought I was being more stupid than usual and gave up. I liked 24ac and 22ac a lot.
I thought this was brilliant.
Id no problem with sick as a parrot as geoff says the question mark indicates a bit of looseness which im always prepared to accept for a great surface reading.
Ive also no problem with measure up for height I took it as meaning measure from the ground up. 9ac and 11ac were both brilliant.
One thing I would say is where was the smut? This is the first Paul I remember without any typical Paul “ooh er missus” moments. Has he been told to clean up his act?
Stiofain
Good, entertaining stuff today. Loved the included for “FLIPSIDE” – ingenious. 11ac and 7dn v enjoyable.
Tom – I made exactly the same ‘mistake’ as you with BELOW PAR (arguably better than UNDER PAR) but eventually twigged it must be DUFFEL COAT (2 words in printed version !).
Was also held up by making 7,15 LENNIE THE LION with no justification. Shows my age….
Lot of nice clues, but frustrated not to finish it.
21d – I thought this worked okay on a strict reading of “classical” to mean Greek/Roman art (which none of the Tates displays, as far as I know).