All posts by Stephen

Instrumented soccer, fall 2013

I just started the spring season in my recreational soccer league last weekend. And I’m still using Adidas’s miCoach system to record statistics in each game. Earlier I showed a couple of individual sessions, with image captures from the miCoach site. Here I’m going to summarize the season, and compare it to the previous season (Summer 2013). Top line summary of the season

  • 11 games, 9/8 – 12/29
  • 8 goals
    • Compared to 1 in Summer 2013
    • All on turf

For the quantities tracked by the Speed Cell, we have a group of measurements, summarized as follows

  • Distance: 4.0 ± 0.6 miles per game, with a best of 5.1 miles on 12/1. (Improved over Summer 2013, 3.9 ± 0.5 mpg.)
  • Sprints: 20.5 ± 4.5 sprints per game, with a best of 30 on 12/1. (Improved over Summer 2013, 18.5 ± 4.7 spg.)
  • Maximum speed: 15.0 ± 0.4 mph, with a best of 15.52 mph on 9/15 and 10/6. (Improved over Summer, 2013 14.5 ± 1.1 mph.)

miCoach offers badges (“achievements”) for various performance levels: on 12/1, 5.1 miles of total distance and 0.55 miles of “hi intensity distance” resulted in the Pro achievements for those two categories. Still haven’t reached the Pro mark for Maximum Speed, which I suspect will require a burst over 16 mph. (On 6/9, 3.9 miles of distance and 15.17 mph maximum speed earned the respective Club achievements. On 7/14, 0.38 miles of high intensity distance earned the corresponding Club achievement.)

I was pretty happy with my showing on December 1, but Sean Ingle’s Sunday article in The Guardian, on Chelsea and England defender Ashley Cole, shows how low on the performance scale these numbers are:

The additional physical demands are clear from Prozone’s data. In 2003-04 Premier League full-backs made an average of 29.5 sprints – any movement greater than seven metres a second – over a game. This season that figure is exactly 50. A decade ago the average recovery time for a full-back between high-intensity activities – any movement greater than 5.5m/s, or a three-quarters speed run – was 56.4sec. Now it is 40.4sec.

Ashley Cole faces life in the slow lane as demands of the job intensify

(Of course, I’m ten years older than Ashley Cole, so I am pleased just to be on the field, uninjured, and possessing a little bit of pace.)

It’s going to be hard to compare the spring season with this one, as the new team only has part-time goalkeepers, and I’ll have to take many more shifts in net. (The two times I played keeper during the fall were 13 sprint games.) Other than working on my metrics, my only goal for this season is to finally score one on the grass fields.

Sprinkler valve break and repair

Early last summer, Nathaniel was in the back yard, practicing his kicks into our KixKube. One particularly strong kick missed the cube, and smashed into the exposed sprinkler valves, breaking through the ¾” PVC pipe below one of the valves. The break led immediately to that portion of the garden and lawn being covered in water, so I rushed to close the water main at the street and then scurried to Home Depot to get a PVC cap and fresh (fast setting) PVC cement.

You can see the cap at the right of the above photo; it’s the piece below the blue PVC cement-stained pipe. The fragments of plastic are the remains of the storage container I placed over the valves to protect them from further misses. (Not successfully.)

I decided to make two improvements when I rebuilt this complex: to add a ball valve before the sprinkler valves, so that I can make repairs without turning off water to the entire house, and to add a third sprinkler valve for a drip system. You can see the ball valve underneath the rightmost valve in the picture below; the new valve is the leftmost.

It took a bit of tweaking to get the joints and valves sealed tight, with one or two connections having to be redone. Once I had the valves watertight and the wiring reconnected, my system testing showed that our Rain8 WLM, which was an X10 wireless-based irrigation control, had suffered a power blow-out as well.

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OpenSprinkler Pi, a photo by schahn on Flickr.

Since the Rain8 WLM had been discontinued, I decided to replace the controller with an OpenSprinkler Pi, using WiFi for wireless access. For the X10-based controller, I had built my own set of irrigation programs for cooler, which had been moving from shell scripts invoking flipit driven by cron(1M) to using Redis for state and eventually to a web server model, but I dropped all of that—for now—in favour of Sprinklers Pi running directly on sprinkles (the Pi). With the combination of a regular and a seeding schedule, I have equivalent (or better, with the Weather Underground integration) capability to the previous implementation. The new system has been working well.

Overseeding

With the watering infrastructure restored, I did our fall overseeding, three months late, using a mix of low-water grass and white clover, topped with new soil and compost. These guys—mature and immature white-crested swallows (Zonotrichia leucophrys nuttalli)—showed up once the grass seed hit the ground (and walkway). Let’s hope they leave enough seed to grow. (The mature one is the one sporting the white crest with black stripes on his head.)

This is the second California animal species or subspecies we’ve mentioned here that is named in honour of Thomas Nuttall. (Earlier in the summer, we saw a Nuttall’s woodpecker.)

Weeding by grid

Now that we’ve begun repairing the lawn with new grass, the final phase will be plucking out the crabgrass that dominated one corner. I’m going to work systematically through the lawn using a grid system, plucking out each crabgrass shoot.

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Grid, a photo by schahn on Flickr.

There’s about ½” of new soil spread over top to provide new nutrients, but there are also some pretty beaten down bare patches. We’ll see what the spring growth brings.

Next steps

Assuming I establish some level of control over the crabgrass, I’ll connect a small drip irrigation system to that unused valve and introduce a corresponding third schedule to the Sprinklers Pi configuration. If that goes well, I’ll add a second valve to the front lawn for drip—unless we decide that even a small front lawn is an indulgence during a severe drought. (In which case, maybe I’ll transplant the sod from the front to the back and go drip-only in the front to the citrus trees and oleander.)

Figuring out 8v8 formations by reduction

For the younger ages of the California competitive leagues the boys have played in, sides are eight players each, and don’t move to the adult 11-a-side game until the spring season of U11. Ben is in his second season of 11-a-side, while Nathaniel has a few seasons of 8-a-side still to go. Since we try to be informed spectators of each, I thought it would be interesting to comment on the 8v8 formations as they relate to the adult formations.

Wikipedia’s coverage of soccer (“association football”) topics is extensive—covering players, club and national teams, tournament histories, and aspects of the game. The article on soccer formations gives an overview of both the historical development of formations and a summary of the current common formations. We’ll use it as a basis for identifying key adult formations; the article covers many more.

For formations with three rows, defenders–midfielders–forwards, an 8 player formation can be derived from an 11 player formation by subtracting one player from each row. Since the four row formations are refinements of the midfielders into a pair of sub ranks, we treat formations like the 4–2–3–1 and 4–3–1–2, as variations of the 4–5–1 and 4–4–2, respectively.

4–4–2 → 3–3–1

You’ll see a lot of teams playing the 3–3–1, as it’s the recommended 8v8 formation in the US Soccer curriculum. Although your striker has to work hard to apply pressure on his or her own, he or she benefits by being the focus of attacks up the middle. This formation has natural width and a well-populated midfield, although I haven’t seen many teams that encourage their outside defenders to make runs forward. (So we see many conservative 3–3–1 teams.) When your team moves up, you’ll find the 4–4–2 is one of the recommended 11v11 formations for U12 in the US Soccer curriculum. (Your striker may find the transition challenging, as they will have to pair with a peer, rather than be the single focus.)

4–3–3 → 3–2–2

The 4–3–3 is the other recommended 11v11 formation for U12 in the US Soccer curriculum, so it’s natural to hope that it’s 8v8 reduced form would be easy to use as well. However, the midfield and forward part of the resulting formation is narrow, meaning that it’s easy for opponents to find space to work through; against a 3–3–1, the 3–2–2 is at a numerical disadvantage in the midfield. I’m not sure I’ve seen any team line up in a 3–2–2.

4–5–1 → 3–4–0

Ben’s team in 2012 ended up playing in a 3–4–0 for much of their spring season. I believe what the coach was trying to address was the forwards’ tendencies to not come back on defense once possession was lost. The drawback is that, without a single striker occupying the defense (to maintain length), the opposing defenders can come forward and capture cleared balls easily. It’s also unclear which of the midfield is responsible for pressuring the opponent, although teams with good individual defensive instincts or training might enjoy the flexibility of having the closest player apply the pressure.

3–4–3 → 2–3–2

Wigan Athletic under Martinez in recent years stood out in the Premier League for playing a 3–4–3. Its reduction, the 2–3–2, might work as a tactic for a 3–3–1 team trying to bring more offense to bear in the final portion of a game. The two defender line will have to be very strong, or your keeper will be very busy.

3–5–2 → 2–4–1

Nathaniel’s team often plays in a 2–4–1 since they have a number of outside midfielders willing to run from goal line to goal line and cover the opposing outside forward when on defense. Risky like the 2–3–2 if the defenders aren’t strong and coordinated, although the extra player in midfield should stop the opponent from finding overloads as easily as they might against a 2–3–2.

5–mn → 4–(m-1)(n-1)

I haven’t seen anyone playing four defenders in 8v8, because we haven’t seen anyone willing to give up most of their offensive chances by clamping down defensively. (Most youth tournaments award points for goals scored, in addition to the game result, so losing 2–3 can be better than tying 0–0. In other areas, you might see youth teams happy to draw…)

Translating per-position comments

If you are trying to describe each position’s responsibilities in an 8v8, the key difference between the responsibilities in the adult formation and in the reduction comes from the change in each row from an odd to an even number of players. That can be made even simpler: the even-numbered rows need to be very clear about how to divide their coverage of the field (left-right or left-center left-center right-right), while the odd-numbered rows should find this allocation clear (solo or left-center-right). For some formations, positions are otherwise almost unchanged: the wide players in the 3–3–1 have the same responsibility to go forward as their counterparts in the 4–4–2. But, much like our striker in the 3–3–1 must learn to coordinate with a second striker in the 4–4–2, so will the central defender in a 3–mn mesh with a partner in a 4–(m+1)(n+1).