Preliminary assessment. moonbus White, Tshotsho Khalapa Black
1. e4
Message from moonbus to Tshotsho: I'll play something classical, to demonstrate some basic principles.
1... e5 2. Ng1f3 Nb8c6 3. Bf1b5
moonbus: This is a standard opening. A good one to learn. You'll run into this one a few thousand times in your chess career. Both sides try to develop pieces quickly and contend for control of the centre.
3... a6
Tshotsho Khalapa: This is how I usaully react, trying to force the bishop backwards. Moonbus: a perfectly playable line for Black. The other common option for Black here is ... Nf6. White has two playable responses to ... a6: either BxN, or retreat the bishop.
4. Bb5a4 Ng8f6 5. O-O
moonbus: Let's start a checklist of things to look at before you make a move. I just castled and left my e-pawn en prise (attacked and undefended). So, here is an item for the mental checklist: 1. Check all pieces (incl. pawns) left en prise. Sometimes it is a trap, sometimes it is an oversight (and believe me, even 2000+ players sometimes miss the obvious), and sometimes the piece (or in this case the pawn) can be easily regained. I invite you to use the RHP 'analyze board' function (if you are comfortable with it) or a real board (if you prefer), and play out the following variation: White castles, and you continue: ... Nxe4; Re1... and then tell me which of the three cases this is: I just blundered my e-pawn, or it's a trap, or I can get the pawn back easily. The main thing is to notice that a piece (or pawn) is hanging and to put that into your growing catalog of items to look for before you make a move. Of course, this applies to leaving your own pieces en prise, too.
5... Nf6xe4
Tshotsho Khalapa: I 've analyzed and I realise you can get the pawn back.
6. d4
moonbus: Correct. I expect to get it back. But first, I'm going to enable some development: I want to get my queen's bishop into the game rapidly, and I want to clear the e-file because your king is still in the centre. Getting the pawn back will be secondary if I can pin your knight in the centre.
6... f6
moonbus: this is probably played to bolster the Black e-pawn, which is understandable. It has two serious disadvantages: 1. f6 was the natural retreat square for the Black knight, and f7-f6 just blocked it. 2. It weakens the king position by opening the diagonal h5-e8.
7. Rf1e1 Ne4d6
moonbus: the knight has no other retreat. On d6 it holds the critical square f7, but it severely hinders Black's further development, blocking both Black bishops.
8. dxe5 Nc6xe5 9. Nf3xe5 Bf8e7
moonbus: remember item one on the mental checklist: there was no reason not to take the White knight, which is hanging, on e5. By not taking fxe5, you are giving me a knight for free.
10. Qd1h5
moonbus: Black is in deep trouble already as a result of the opening of the h5-e8 diagonal. The natural retreat square for the Black knight was f6, but the prior pawn move f7-f6 blocked it and opened a diagonal of attack for White. A Black knight on f6 would have prevented this.