While there was a lot of positive feedback from last week’s post on blocked vs. random practice, there was also a bit of confusion. I suppose the term ‘random’ can be a bit misleading. To clear the air, this week’s post will attempt to clarify the supposed dichotomy between blocked and random practice and offer a slightly different perspective to the argument. Furthermore, there are 2 other forms of practice - called ‘variable practice’ and ‘constant practice’, which can be influenced by both block and random approaches. Lastly, several examples of each practice type will be offered and described, along with the 'why' behind their use.
Random and Block - A Closer Look
The term ‘random’ has been cited in scientific journals for decades. Researchers have been studying this form of practice since the 70s - and hypotheses were argued even earlier than that. While it may not be the best of terms in modern day training circles, the term is here to stay. It’s important to note that while the term may imply disorganization, that’s not at all what it signifies.
To the contrary, practices can (and should) be organized and structured using both random and/or block approaches. These practice types simply refer to the order with which various tasks are rehearsed - i.e. are tasks rehearsed one at a time (block), or is their order mixed (random). One very important caveat (which you’ll need to know for later) - BOTH forms of practice target MULTIPLE motor programs (tasks and skills) within a practice session. All that means is that you could practice a variety of skills, all in one session. If you were to take a block approach, you would practice forehands first, then backhands, then volleys and so on. In contrast, with a random approach, you may mix up the order slightly - 1 FH, 1 BH, 1 V, then repeat. Or you could change the order significantly - 1 FH, 1 V, 1 BH, 1 V, 1 BH, 1 FH and so on. While there are a number of possibilities, it’s important to be aware of the differences as they will likely shape the way coaches organize their training sessions.
Variable and Constant Practice - Definitions and Differences
What about practices where players are practicing only ONE type of skill at a time? While perhaps not as common, sometimes a student will say, "I'd really like to focus on my forehand today". In this particular circumstance, you could work on only 1 type of forehand - attacking forehand up the line - OR you could hit different types of forehands - one rally forehand crosscourt, one attacking forehand up the line and so on. As you probably guessed, the latter approach is a form of constant practice while the former is a form of variable practice. So, in constant practice you simply work on one particular skill, in one particular circumstance, over and over, with no variations or changes. In variable (or varied) practice, you'd work on one skill (forehands), within a variety of circumstances - changes in court position, shot height and length requirements and so on.
Similar to what we saw last week with random practice, varied practice seems to augment long-term learning to a greater degree when compared to constant practice. While the end-result is similar to random (in that the performance benefits are higher compared to either block and/or constant practice), the way in which variable and random effect learning, differ.
Random is presumed to work due to the ‘trial-to-trial forgetting’ of the various task solutions because there is very little repetition of the same task, which helps to develop distinctive representations of theses tasks in our long-term memories (Schmidt and Wrisber 2000). Variable practice, on the other hand, accelerates learning because it helps develop a variety of ‘schemas’ that help determine what parameter is needed for success in task execution. Let's take our variable forehand practice example from earlier to illustrate this point. Recall that the session consists of forehands only, but I’m practicing these forehands from different parts of the court, with different tactical intentions and varied executions. Even though I'm practicing these forehands from 1m behind the baseline, when in a match setting and I’m forced to play a forehand from 2m behind the baseline, I can call upon the appropriate motor parameter to still achieve a similar outcome (hitting with depth, for instance). This allows a performer to produce effective outcomes based on continuously varied environmental demands.
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Variable-Random vs. Variable-Block
I know this can be a little confusing but bear with me for a second. When using a variable practice approach, it can be further compartmentalized as either variable-random OR variable-block. For example, if a player is practicing their serve, they could, for instance, hit 20 first serve out wide on the deuce court, 20 first serves up the tee and 20 first serves into the body (look at the video example above). This would be a variable-block practice format. On the other hand, they could mix all of these serves randomly, which would classify the practice under a variable-random format.
You may be asking yourself, is all this practice talk really necessary? In my opinion, the answer is yes. Like we mentioned in last week’s post, knowing when to implement each practice type takes an understanding of a number of factors - what’s the training age of your player; what’s the phase of training; what’s their mental status on that particular day...and so on. Generally speaking, the goal of a training session, will ultimately dictate the type of practice format a coach uses. For instance, if a coach deems that a player has technical deficiencies with their forehand, they may block that skill off, feed a consistent ball, and allow the repetition to sink in.
Of course, as many of you know, simply doing that won’t help them compete at a high level, let alone win at that level. The player must be capable of transferring the skill into a tactical scenario. The next aim then, may be to work on a specific tactical situation involving that player’s forehand. Perhaps when receiving a deep heavy ball to the forehand corner. In this case, the player must do more than simply focus on 'technique'. They must anticipate where the ball is heading, perceive it's depth, make a decision and then react with a movement. Lastly, the player must execute their shot - which also requires a decision based on a number of factors, including where their opponent is standing on the opposite side of the net, and what phase of play the player believes they are in. In these scenarios, using a variable-random practice type may have the biggest impact.
Here’s a quote from friend and colleague of mine that summarizes this point well:
“The goal (the big ‘why') of all this is to elevate the importance of learning perception and decision-making...which are just as important as the technical movements (it is less effective to teach an open skill sport like a closed skill sport by pushing perception & decision-making down the priority list a ways).”
Interpretations and Conclusions
I spoke to 2 mentors of mine in the last week regarding this topic - both have coached world-class athletes. One coached a former top 10 ATP player and the other an Olympic champion. While they come from 2 different sporting backgrounds, their messages were similar...is there really such a thing as true varied/random and true constant/block practice? One coach argued that, when a basketball player practices their jump shot from the same spot, in construct it may look like the same shot (constant/block), but in content, it differs. Put another way, every shot is slightly different compared to the last...the angle with which they release the ball won’t be the same, the amount of height they get off their jump will vary with each shot. Even the athlete him/herself is different - as time passes, fatigue (both mental and physical) set in, hydration status changes, appetite and so on. The other coach echoed a similar sentiment, saying that a cross-court forehand drill can be looked at as random/varied. Because each shot is an entity in and of itself. Look at the video below, it's an example of a drill in which the player knows the direction (more or less) of the oncoming shot...but each shot is different than the last. Based on this, here's what I am proposing...the practice-continuum. Learning isn't black or white, and neither is the 'how' with which we learn. In a sport like tennis, with so many possible variations in decision-making and execution, I believe drills can be set up in varying ways to be either slightly more or slightly less varied.
In any case, the above coach examples are in line with Bernstein’s (a pioneer in motor learning) theory more than 50 years ago,
“The process of practice towards the achievement of new motor habits essentially consists in the gradual success of a search for optimal motor solutions to the appropriate problems. Because of this, practice, when properly undertaken, does not consist in repeating the means of solution of a motor problem time after time, but in the process of solving this problem again and again”
While I’m not sure exactly how Bernstein would break this down during an actual practice session, I’d argue that many ‘live ball’ repetitive drills have value because of this process of solving a problem over and over. Each ball in a simple depth drill is a new problem we must solve. But to do so, we must acknowledge the unique nuances of each movement, decision and shot execution. This in turn, will dictate both the organization of practice and it's aim...