One of the main technical practices that we recommend for teams is pair programming. Under pair programming, two people work on the same piece of code, with each checking the other's work in real time. It's a great way to boost the quality of the code delivered. It's not just code either. It works for testers (one of the most effective pairs is a developer and a tester pairing on something), UX designers, business process folks and so on. Any sort of work can benefit from a second pair of eyes.
Why then do agile coaches tend to work alone? It's very rare to see two coaches working together on anything. While we teach pairing, we coaches tend to work solo. I think this is unfortunate. On the few occasions where I have had the opportunity to work closely with another coach, it has always been a really good experience. So why then don't we do it more often?
The main reason given for coaches working solo is scarcity - there aren't enough to go around already so we certainly can't afford to have two coaches on anything. The other argument is cost - coaches are expensive and our project can't afford two of them. Incidentally, these are pretty much the same arguments that get thrown around when pair programming is mentioned - too expensive, scarce devs and so on.
The cost argument is pretty simple to dispel. It's not about adding another full time coach to a project, it's more about sharing work around so that multiple coaches can participate. So rather than having one coach 100% on a project (or set of projects) why not have them 60% on that set of projects with another coach filling in 40% (and the reverse for the other coach), so two coaches share the set of projects between them. One coach is the lead in each area and the other works as a backup. The same applies for scarcity. Unless you only have one coach, the coaches you have can pair.
Something else that gets mentioned a lot is that having a single coach allows the team to form a close trust relationship with their coach; adding extra people into the mix could dilute that relationship and make coaching harder. This one I have a lot more time for. Forming that coaching relationship is harder when you have multiple coaches, particularly when their coaching styles are quite different. You do need to take some care to make sure that your coach pair is well aligned in their coaching. I don't mean having identical coaching styles, but having a common vocabulary so one coach isn't calling it a review while the other is calling it a showcase. That just confuses the heck out of teams. The coaches need to be talking the same language and have a good common understanding of what the team needs.
Ok. That's the negatives of pair coaching. What about the positives? The first is availability. If a coach is sick or away, there is someone there who already knows the team and can cover. This gives the team continuity. This also applies if one coach leaves. The team will have one familiar face who can introduce a replacement coach into the pair.
It also helps when you have multiple teams who may all have standups or other ceremonies at the same time. Two coaches can be in more places at once than one coach (twice as many for the mathematically minded) so the pair can deal better with scheduling conflicts than a single coach.
The big benefit though is the same as for pair programming - quality. Pair coaching simply gives higher quality coaching. Just as two sets of eyes on a piece of code gives better results than one, two pairs of eyes on a team gives better results than one. One coach will pick up things that the other coach misses. We all have different perspectives, likes, dislikes and other biases that we bring to an engagement. These form a filter between reality and what we perceive as reality. Having another pair of eyes with a different filter can help us see reality more clearly.
Having another pair of eyes also helps with our own development as coaches. When you coach solo, the only person who can see how well you are doing is you. We all tend to overestimate how good we are at things. We tend to get stuck with our preferred way of doing things and discount alternative approaches. Having a second pair of eyes along gives us someone who can objectively assess how we are doing and give (constructive) feedback. They can also suggest alternative approaches that we may not consider. The occasions where I have been able to pair have been the biggest contributors to my development as a coach. I learned so much from pairing. I had my assumptions challenged, my skills tested and my eyes opened.
So, coaching in a pair gives a better result for the team and a better result for the coaches. Done right, it costs no more. If you have never tried coaching as a pair, I would strongly advise you to give it a go. Don't be a lone wolf - pair up.