The first thought to beat aggro is to run creature removal. Goblins is different though, because if all you do is run cheap mass removal like
Pyroclasm on top of
Terminus, even a lot of it, I don't think it will matter. The reason that we lose against goblins is that even with mass removal, we don't have a great clock, so Goblins has plenty of time to recover with card advantage. Additionally, without a good clock, lock pieces like
Moat,
Ensnaring Bridge or
Peacekeeper are pretty terrible because the goblins player has forever to find an answer, and most answers they use can't be dealt with using counters (
Gempalm Incinerator,
Tuktuk Scrapper via
Aether Vial or
Cavern of Souls, or our favorite
Krosan Grip).
In light of this, I think Goblins is always going to be a rough matchup, but in spite of any answers goblins may have (I'm looking at you
Stingscourger), I think Batterskull is the best option against them. The lifegain + vigilance is a nightmare for them, but more importantly it gives us a clock. As mentioned, our lack of clock is what leads to failure oftentimes in that matchup, so "answers" to goblins that don't provide a clock are likely going to fail, which is why I really like SFM/batterskull in this scenario since I don't see anything else really providing that clock while also being a pain for the goblins player to play around. To support the stoneblade approach to beating goblins I would start by having 2-3
Stoneforge Mystic and 1 Batterskull in the main and 1-2 SFM (and maybe even a second batterskull) in the side. This way you have a good consistency of seeing them, and if one skull is destroyed you have access to another. I would just skip
Umezawa's Jitte because it won't provide the clock we need, and almost any blocker they have will deal with any Jitte-wielding creature besides a flying Clique.
Yes, this is a maindeck choice (or sacrifice, depending on how you look at it) that you must make. However, if you truly want to beat goblins, this is a sacrifice you must make because relying just on your sideboard with a stock miracles list will not let you consistently beat goblins. I think that SFM + Batterskull already plays well into our control strategy (hard to deal with, relatively cheap costs with SFM, stabilizes board, and provides a clock) so it's an easy maindeck choice to make. Then you can supplement this strategy by having even more cards from your sideboard to help your goblins matchup (
Humility,
Porphyry Nodes,
Pyrocalsm etc.), and only then do I think you have a reasonable chance at beating goblins consistently.
I think also that siding in extra
Entreat the Angels (or maybe two) is also a viable approach, although sometimes Entreat can be slow and clog your deck with many miracles post-board. Entreat is about the only card that can legitimately steal the game from a goblins player, even in situations where you would not be able to win in almost any other way. Having extra Entreats is also great against a lot of slightly slower, more controlling-type decks, so I consider it a pretty versatile sideboard card.