Chapter 27 Quiz

Instructions: Select the best answer for each question. Some questions may have multiple correct answers; select all that apply where indicated.

Question 1

What is the standard formula for total end-to-end latency in a real-time analytics pipeline?

(a) $L_{\text{total}} = L_{\text{capture}} \times L_{\text{transmit}} \times L_{\text{process}} \times L_{\text{render}}$ (b) $L_{\text{total}} = L_{\text{capture}} + L_{\text{transmit}} + L_{\text{process}} + L_{\text{render}}$ (c) $L_{\text{total}} = \max(L_{\text{capture}}, L_{\text{transmit}}, L_{\text{process}}, L_{\text{render}})$ (d) $L_{\text{total}} = L_{\text{process}} + L_{\text{render}}$

Answer: (b). The total latency is the sum of all sequential stages in the pipeline. Each stage adds its own delay to the total time from event to insight.

Question 2

Which streaming architecture treats all data---both real-time and historical---as streams?

(a) Lambda Architecture (b) Kappa Architecture (c) Event-Driven Architecture (d) Microservices Architecture

Answer: (b). Kappa Architecture simplifies Lambda by eliminating the separate batch layer. All data is treated as an unbounded stream, with historical data being a stream that has already been consumed.

Question 3

A tracking system operates at 25 Hz and tracks 23 entities. How many position updates are generated per second?

(a) 25 (b) 230 (c) 575 (d) 5,750

Answer: (c). 25 frames/second times 23 entities = 575 position updates per second.

Question 4

Which serialization format offers zero-copy deserialization, making it ideal for ultra-low-latency scenarios?

(a) JSON (b) Protocol Buffers (c) Apache Avro (d) FlatBuffers

Answer: (d). FlatBuffers allows accessing serialized data without parsing or unpacking, achieving zero-copy deserialization.

Question 5

In the pressing intensity formula, what does the indicator function $\mathbb{1}[d_i^{\text{ball}}(t) < R]$ represent?

(a) Whether the player is on the home team (b) Whether the player is within the pressing engagement radius of the ball (c) Whether the player is sprinting (d) Whether the player is facing the goal

Answer: (b). The indicator function filters the calculation to include only players within the radius $R$ of the ball, ensuring that only players actually engaged in the press contribute to the metric.

Question 6

Which algorithm is used for role assignment in formation detection to minimize total positional displacement?

(a) K-means clustering (b) Hungarian algorithm (c) Dijkstra's algorithm (d) Gradient descent

Answer: (b). The Hungarian algorithm solves the assignment problem optimally, matching each player to a formation role to minimize the total squared displacement.

Question 7

What model is applied for temporal smoothing in formation detection to prevent spurious formation switches?

(a) Kalman filter (b) Convolutional neural network (c) Hidden Markov model (d) Random forest

Answer: (c). A hidden Markov model treats formations as hidden states and observed positional data as emissions, providing temporal consistency through transition probabilities.

Question 8

In the momentum score formula $M(t) = \alpha \cdot \text{xT}_{\text{rate}} + \beta \cdot \text{PI} + \gamma \cdot \text{Poss} + \delta \cdot \text{Terr}$, what do the weights $\alpha, \beta, \gamma, \delta$ represent?

(a) Fixed constants defined by FIFA (b) Randomly assigned values (c) Learned weights calibrated from historical data (d) Player-specific multipliers

Answer: (c). The weights are learned by regressing the momentum components against subsequent goal-scoring probability, calibrating each component's contribution to predictive accuracy.

Question 9

What is the recommended maximum total latency for critical alerts (e.g., injury risk) in a bench-side system?

(a) 50 ms (b) 500 ms (c) 3 seconds (d) 10 seconds

Answer: (b). Critical alerts require $L_{\text{total}} < 500$ ms to enable timely intervention, while aggregate metrics have a more relaxed 3-second budget.

Question 10

In the substitution optimization model, what does the remaining influence factor $R(t)$ represent?

(a) The number of remaining substitutions (b) The proportion of match time left for the substitution to have effect (c) The player's remaining stamina (d) The referee's added time estimate

Answer: (b). $R(t)$ quantifies how much of the match remains for the substitution to influence the outcome. A substitution in the 89th minute has a much smaller $R(t)$ than one in the 60th minute.

Question 11

According to the chapter, what is the "two-second rule" for bench-side visualizations?

(a) Visualizations should update every two seconds (b) A coach must be able to extract the key message within two seconds of glancing at the display (c) The system should buffer two seconds of data before rendering (d) Alerts should persist on screen for exactly two seconds

Answer: (b). The two-second rule is a hard design constraint reflecting the reality that coaches have extremely limited attention budgets during a live match.

Question 12

Which of the following is NOT a standard level in the dashboard design hierarchy?

(a) Level 0 --- Glanceable Summary (b) Level 1 --- Tactical Overview (c) Level 2 --- Detailed Analysis (d) Level 4 --- Machine Learning Model Retraining

Answer: (d). The hierarchy consists of four levels (0--3): Glanceable Summary, Tactical Overview, Detailed Analysis, and Deep Dive. Model retraining is not a dashboard level.

Question 13

What is a Voronoi tessellation used for in real-time pitch visualization?

(a) Computing expected goals (b) Showing which team "owns" which area of the pitch (c) Tracking ball trajectory (d) Measuring player heart rates

Answer: (b). Voronoi tessellation partitions the pitch into regions based on which player is closest to each point, providing an intuitive visualization of space control.

Question 14

What minimum display brightness is recommended for outdoor bench-side use?

(a) 250 nits (b) 500 nits (c) 1,000+ nits (d) 2,000+ nits

Answer: (c). High-brightness displays of 1,000+ nits are necessary for visibility in direct sunlight conditions commonly encountered in outdoor stadium settings.

Question 15

What is the "golden hour" in post-match analysis?

(a) The hour before kickoff when the analyst sets up equipment (b) The first 60 minutes after the final whistle when analysis is most valuable (c) The peak hour of match intensity, typically around minute 60--75 (d) The hour allocated for press conferences

Answer: (b). The golden hour refers to the first 60 minutes after the match ends, when player memories are freshest, media need data-driven talking points, and recovery protocols must be initiated.

Question 16

In the automated report generation pipeline, what comes immediately after data reconciliation?

(a) Distribution (b) Narrative generation (c) Statistical computation (d) Visualization package

Answer: (c). The pipeline follows the sequence: data reconciliation, statistical computation, narrative generation, visualization package, distribution.

Question 17

Which windowing strategy uses variable-size windows separated by gaps in the event stream?

(a) Tumbling windows (b) Sliding windows (c) Session windows (d) Hopping windows

Answer: (c). Session windows group events into variable-length sequences separated by periods of inactivity (gaps), such as grouping passes into possession sequences separated by turnovers.

Question 18

What is the relationship between window size $W$ and metric stability?

(a) Stability is proportional to $W^2$ (b) Stability is proportional to $\sqrt{W}$ (c) Stability is proportional to $1/W$ (d) Stability is independent of $W$

Answer: (b). Stability is proportional to $\sqrt{W}$, meaning larger windows produce smoother metrics but at the cost of responsiveness, which is proportional to $1/W$.

Question 19

What system availability target is recommended for match-day deployments over a 120-minute window?

(a) 95% (b) 99% (c) 99.9% (d) 99.99%

Answer: (c). A 99.9% uptime target allows for approximately 7 seconds of cumulative downtime across a 120-minute match window.

Question 20

Which of the following is the recommended encryption standard for stored match data?

(a) AES-128 (b) AES-256 (c) RSA-2048 (d) DES

Answer: (b). AES-256 encryption at rest is the recommended standard for protecting sensitive match and player data.

Question 21 (Select all that apply)

Which of the following are valid state management strategies for real-time pipelines?

(a) In-memory state (b) Checkpointed state (c) External state stores (d) Stateless processing only

Answer: (a), (b), (c). All three are valid strategies with different tradeoffs in performance, durability, and complexity. Stateless processing is not sufficient for metrics that require accumulation over time.

Question 22

In the metabolic power formula, what does the "equivalent slope" (ES) term represent?

(a) The pitch gradient at the player's location (b) A mathematical mapping of acceleration to the slope of an equivalent uphill run (c) The slope of the player's speed over time (d) The terrain difficulty factor

Answer: (b). The equivalent slope converts acceleration into the slope of an equivalent uphill run, allowing metabolic cost to be estimated from velocity and acceleration data.

Question 23

What type of testing involves deliberately introducing failures to verify graceful degradation?

(a) Unit testing (b) Integration testing (c) Chaos testing (d) Acceptance testing

Answer: (c). Chaos testing deliberately introduces failures such as network drops, sensor outages, and data corruption to verify that the system degrades gracefully rather than failing catastrophically.

Question 24

In horizontal scaling for a scouting network, how is the event stream partitioned?

(a) By player ID (b) By event type (c) By match ID (d) By timestamp

Answer: (c). Partitioning by match ID ensures that all data for a single match is processed on the same compute node, maintaining locality for match-level analytics while distributing concurrent matches across nodes.

Question 25

According to the chapter, what is the primary role of the analyst in a real-time decision-support system?

(a) Operating the tracking cameras (b) Translating statistical signals into tactical language for coaches (c) Making substitution decisions independently (d) Managing the IT infrastructure during the match

Answer: (b). The analyst serves as a translator between the statistical output of the decision-support system and the tactical language that coaches can act upon. The system recommends; the human decides.