I think others have noted that there are five mains teams who have a chance (Grammar, Joeys, High, Scots and Riverview). Personally though, I think only three teams that have good chances (Grammar, Joeys and High). I'll be going through each school in order of what I feel to be their likelihood of winning.
1. Grammar
Grammar are probably my favourites coming into this GPS season due to a few reasons. Winning ISDA obviously shows the strength of their team, with strong individual performances from the three year 12s on the team (Kasra, Remy and Daniel) in the finals helping to secure them the trophy. Historically they have always performed well in the GPS competition and I think, given the success that they saw in ISDA, they should be good to go for GPS. Overall, a very strong team who I'd probably predict two reps from in GPS 1sts.
28% chance to win
Predicted Record of 6-1
2. SBHS
SBHS performed poorly in Eastside but despite that, I think they'll still do well in GPS. Eastside has never been a good indicator for SBHS's performance in GPS (maybe due to its wackier topics under Mikey Xu?) so I don't think much weight should be placed on their results. In PDC however, they've done very well, with their A team reaching the top 4 and defeating James Ruse Year 12 twice (who have Darshanik Aryal on their team) which at least suggests that they have consistency within their team. In terms of standout talent, I only know of Abrar Chowdhury in Year 12 who was in CHS 2nds last year but I've been told that in this year's CHS squad, there are three members from SBHS. This team also defeated Grammar 2nds last year and is historically pretty successful, maybe a member in GPS 2nds? (as the top debaters go to CHS). They should be a competitor in this season.
27% chance to win
Predicted Record of 6-1
3. Joeys
Joeys staged a surprising performance last year, winning both 1sts and 2nds GPS in a field which had exceptionally strong Grammar and SBHS teams. The reason I had them at 3rd is mainly because one, their ISDA performance, while excellent, saw them falling short to an Aloys team who Grammar proceeded to fairly clearly win against (although topic selection obviously played a part) and two, I don't know of any standout talent from this team as opposed to Grammar and High who appear to have some excellent standout speakers. However, DON'T underestimate this team, despite having them at 3rd, I wouldn't be surprised if they won and I think all these three teams have excellent chances in the upcoming comp and I still have them at a 6-1 record.
26% chance to win
Predicted Record of 6-1
4. Scots
Scots are probably the last true contender this season? Perfect group stage (albeit in a relatively easy division) and a State Speaker (Jehiel Pather) are big positives for their team. They did however lose to a Barker team (containing National Reserve Iris Lee) who proceeded to lose to Grammar and I don't know how much their State speaker can take them in GPS. Still a good team who I could see beating one of the three above teams. However, I would be pretty surprised if they won it all (still not out of the picture however). They'll definitely be a good team at the least.
14% chance to win
Predicted Record of 4-3
5. Riverview
Riverview are a good but not great team. They won 6 in a weaker Pool D ISDA, showing consistency at the minimum in being able to beat weaker teams. They lost in a tough quarters matchup with Joeys, probably showing their ceiling. Should still be a good team and upsets I think are possible but I don't expect them to be near title contention.
3% chance to win
Predicted Record of 3-4
6. Shore
Shore went well in a relatively weak Pool A, getting second with 5-2. They also have a state speaker (Michael Kwak) who is somehow in their 2nd grade and honestly, this team has much better chances to win 2nds than 1sts (I mean they made Semis ISDA Senior B). Historically, they've been decent and I think they could beat Riverview, possibly getting into the top half if Scots slide. But like Riverview, I don't see them near title contention.
2% chance to win
Predicted Record of 2-5
7. Kings
So, Kings and Newington are probably both the weakest teams in this comp this year by a fair margin. Both were in Pool C, finishing second last and last respectively and failing to get to the knockouts. Kings won two debates but Newington beat Kings so I honestly have no clue how these two will finish. I'd probably put Kings at 7th due to winning two at least against somewhat stronger schools (MLC and Cranbrook). I don't see either of these teams even pulling off upsets barring the case of wildly imbalanced topics.
<1% chance to win
Predicted Record of 1-6
8. Newington
I don't even think Newington are that bad of a team but GPS is always incredibly stacked and their ISDA division (C) was pretty strong all the way down. For more, see above comments in the Kings section.
<1% chance to win
Predicted Record of 0-7
And that's a wrap on my GPS thoughts. I'll be very interested to see the performances of certain teams and speakers. Some key debates to look out for include Joeys vs Grammar (4/8), Joeys vs High (18/8) and High vs Grammar (8/9). Scots vs Riverview (28/7) in the first week should also be interesting to gauge the strength of those two teams. But I think that's all to discuss, looking forward to the season and wishing all teams the best of luck!